1uzfe Wiring

How to wire up a 1uz-fe
By
Nigel Wade
This is how you wire up an EFI Engine. The 1uzfe, 2uzfe, and 3uzfe wiring guide
(including diagrams). A comprehensive and detailed guide with over 11,000 views
on the oldschool.co.nz forums.
Note: this document is unfinished: most of the information is completed and a

best effort has been made there however a number of grammatical errors and
well, a better effort could be made. However due to commits at university it is no
longer possible to continue with this document until 23/12/2012.
Nigel Wade is a New Zealander who grew familiar with the engine and it’s wiring as a hobby and
decided to share his knowledge to benefit others.
Table of Contents
Table of Contents .................................................................................................. 2

1 Lets begin ....................................................................................................... 8
2 Quick and Fast .............................................................................................. 10
2.1 - Quick and Dirty, this is what you connect + thoughts ................................ 10
2.1.1 In the ecu loom: ............................................................................... 10

2.1.2 In the wiring loom: ........................................................................... 10
2.1.3 Neutral Start Switch .......................................................................... 10
2.1.4 Cold Start Injector ............................................................................ 10
2.2 Anti-Flooding Feature .............................................................................. 11

2.3 Just to get it running ............................................................................... 11
2.4 - The Method: this is how you wire up an engine. ....................................... 12
2.4.1 The Method for counting the pins is: ................................................... 12

2.4.2 Get it right: this is no time for mistakes ............................................... 13
2.4.3 Do you need four relays ? .................................................................. 14
2.4.4 A few fuses too, ................................................................................ 14
2.4.5 The dash plug in the ecu’s end of the bundle. ....................................... 14
2.4.6 You will need to add in a plug ............................................................. 14
2.4.7 Important to get the Check Light Running ASAP ................................... 15
2.4.8 The ECU must be ok for the light to blink ............................................. 15
2.4.9 Your motor do it your way. ................................................................ 15
2.5 - Toyota wiring follows a certain kind of logic, ............................................ 16
2.5.1 Primary Sensors ............................................................................... 16

2.5.2 Secondary Sensors ........................................................................... 16
2.6 Missing the fourth plug ? a Dirty fix. .......................................................... 17
3 The Pin & Acronyms ....................................................................................... 18
3.1 The factory diagrams ............................................................................... 18

3.2 Using the letter codes below ..................................................................... 18
4 Pin Functions. ............................................................................................... 19
4.1 16 pin.................................................................................................... 19
4.1.1 FPR Fuel Pump Relay, ........................................................................ 20

4.1.2 THG Gas Temp Sensor ....................................................................... 20
4.1.3 W Check Engine Light ........................................................................ 21
4.1.4 FC Fuel Pump controller ..................................................................... 21
4.1.5 TE1 - diagnostic ................................................................................ 21
4.1.6 OIL Auto Oil Temp sensor ................................................................. 21
4.1.7 KNK1 Top left Knock Sensor ............................................................... 21
4.1.8 PGR1 Evap Valve .............................................................................. 21
4.1.9 PR Fuel Pressure Control Valve, .......................................................... 21
4.1.10 THW0 Air Conditioning ....................................................................... 21
4.1.11 KNK2 Top Center Knock Sensor, ......................................................... 21
4.1.12 L(+)Gear Selector Indicator (Low) ...................................................... 21
4.1.13 2(+) Gear Selector Indicator (2nd) ..................................................... 22
4.1.14 R(+)Gear Selector Indicator (Reverse) ................................................ 22
4.1.15 EO3 Earth Right Side Head, ................................................................ 22
4.1.16 E1 Earth In Common, ........................................................................ 22
4.2 22 Pin.................................................................................................... 22
4.2.1 VC TPS – pin 4, ................................................................................ 23

4.2.2 NCO(+)Over drive direct clutch speed sensor ....................................... 23
4.2.3 NCO(-) Over drive direct clutch speed sensor ....................................... 23
4.2.4 SP2 (-)Speed Sensor ......................................................................... 23
4.2.5 NE(+) Crank Sensor .......................................................................... 23
4.2.6 NE(-)Crank Sensor ............................................................................ 23
4.2.7 VTA1 TPS pin 3, ................................................................................ 23
4.2.8 VG Mass Air Flow Meter Pin 2, ............................................................ 24
4.2.9 SP2(+) Speed Sensor ........................................................................ 24
4.2.10 G1(+) Camshaft position sensor left bank, ........................................... 24
4.2.11 G1(-) Camshaft position sensor left bank, ............................................ 24
4.2.12 VTA2 Traction Control – pin 4 sub TPS ................................................. 24
4.2.13 OXL1 left O2 sensor .......................................................................... 24
4.2.14 HTR1 O2 sensor pin 1 – (right), .......................................................... 24
4.2.15 HTL1 O2 sensor pin 2 – (Left), ........................................................... 24
4.2.16 G2(+) right camshaft sensor, ............................................................. 24
4.2.17 G2(ES) right camshaft sensor, ............................................................ 24
4.2.18 THA – Air Temp (AFM/MAF Pin 3) ........................................................ 24
4.2.19 OXR1 Right O2 sensor ....................................................................... 24
4.2.20 THW Coolant Temp Sensor ................................................................. 24
4.2.21 EVG Mass Air Flow meter ................................................................... 25
4.2.22 E2 Common Sensor Earth, ................................................................. 25
4.3 28 Pin.................................................................................................... 25
4.3.1 HTR2 O2 Sensor Sub Right................................................................. 26
4.3.2 OXR2 O2 Sensor Sub Right ................................................................ 26
4.3.3 OXL2 O2 Sensor Sub Right ................................................................. 26
4.3.4 HTL2 O2 Sensor Sub Left ................................................................... 26
4.3.5 PWR (-) Stops starting when not in park .............................................. 26
4.3.6 PWRL(+) Return signal for the above .................................................. 26
4.3.7 ODI Cruise Control ............................................................................ 26
4.3.8 AD .................................................................................................. 26
4.3.9 IGSW – Turns Ecu on. ....................................................................... 27
4.3.10 SDL Data Link connector .................................................................... 27
4.3.11 SEL O2 sensor secondary ................................................................... 27
4.3.12 SPDM Speedo Signal ......................................................................... 27
4.3.13 ACMG Air Conditioning....................................................................... 27
4.3.14 BATT - ECU constant pwr supply ......................................................... 27
4.3.15 ELS ................................................................................................. 27
4.3.16 BK .................................................................................................. 27
4.3.17 TPC - Vapour Pressure sensor ............................................................. 27
4.3.18 PTNK Vapour Pressure sensor ............................................................. 27
4.3.19 L1 Electronic Suspension, .................................................................. 27
4.3.20 AC - Air Conditioning ......................................................................... 27
4.3.21 NEO - Anti Lock Brakes, ..................................................................... 27
4.3.22 +B - ECU switched power .................................................................. 28
4.3.23 n/a ................................................................................................. 28
4.3.24 MREL - EFI Relay (turn on)................................................................. 28
4.3.25 EFI (-) - Anti Lock Breaks, ................................................................. 28
4.3.26 EFI (+) - Anti Lock Breaks, ................................................................ 28
4.3.27 TRA - Anti Lock Breaks, ..................................................................... 28
4.3.28 3 - Auto Trans (3) Light ..................................................................... 28
4.4 34 Pin Plug ............................................................................................. 28
4.4.1 SLN + (Auto) Electric Solenoid #4 ...................................................... 29

4.4.2 SLU + (Auto) Electric Solenoid #3 ...................................................... 29
4.4.3 SLN - (Auto) Electric Solenoid #4 ....................................................... 29
4.4.4 SLU - (Auto) Electric Solenoid #3........................................................ 29
4.4.5 #60 Injector 6 .................................................................................. 30
4.4.6 #50 Injector 5 .................................................................................. 30
4.4.7 #40 Injector 4 .................................................................................. 30
4.4.8 #30 Injector 3 .................................................................................. 30
4.4.9 #20 Injector 2 .................................................................................. 30
4.4.10 #10 Injector 1 .................................................................................. 30
4.4.11 S1 - (Auto) Electric Solenoid #1 ......................................................... 30
4.4.12 IGF1 Igniter ..................................................................................... 30
4.4.13 STA - Tells Ecu engine is being started ................................................ 30
4.4.14 NSW - Neutral Start Switch ................................................................ 31
4.4.15 #80 Injector 8 .................................................................................. 31
4.4.16 #70 Injector 7 .................................................................................. 31
4.4.17 S2 - (Auto) Electric Solenoid #2 ......................................................... 31
4.4.18 Blank .............................................................................................. 31
4.4.19 Blank .............................................................................................. 31
4.4.20 ISC4 - Idle Control Valve ................................................................... 31
4.4.21 ISC3- Idle Control Valve .................................................................... 31
4.4.24 IGT1 Ignitor ..................................................................................... 32
4.4.25 IGT1 Ignitor ..................................................................................... 32
4.4.26 IGF2 Ignitor ..................................................................................... 32
4.4.27 EGR4 - EGR Valve ............................................................................. 32
4.4.28 EGR3 - EGR Valve ............................................................................. 32
4.4.29 EGR2- EGR Valve .............................................................................. 32
4.4.30 EGR1- EGR Valve .............................................................................. 32
4.4.31 IDL2 - traction control system ............................................................ 32
4.4.32 IDL1 - TPS ....................................................................................... 32
4.4.33 E02 - Earth Left Rear Cylinder Head .................................................... 32
4.4.34 EO1 - Earth Left Rear Cylinder Head. ................................................... 32
5 The ECU is a learning ecu ............................................................................... 32

6 It wont start for no obvious reason .................................................................. 33
6.1 A Story .................................................................................................. 33
7 Watch for mechanical failures at start up .......................................................... 34

8 Pulsing, but patterned idle .............................................................................. 34
9 The Details ................................................................................................... 36
9.1 How to test the healthiness of an ecu ........................................................ 36

9.2 - Looms and ECU's / Transmissions ........................................................... 38
9.2.1 Looms and ECU's .............................................................................. 38

9.2.2 Transmissions .................................................................................. 38
9.3 - Working with the Loom Casings and Plugs. .............................................. 39

9.3.1 Free the loom ...................................................................................... 39
9.4 Here is what most often happens .............................................................. 40

9.5 Brittle from heat, covered in corrosive dust ................................................ 40
9.6 Heat damage .......................................................................................... 41
9.7 Heat damage reasons ? ........................................................................... 41
9.8 Before removing the lower plastic housing ................................................. 41
9.9 When you've got the loom off ................................................................... 42
9.10 Wiring up the MAF / Air Sensor ................................................................. 42
9.10.1 Karmen Vortex Air Flow Meter ............................................................ 43

9.10.2 Karman Vortex Air Flow Meter Operation ............................................. 43
9.10.3 Later Model Plastic Type .................................................................... 44
9.11 Wiring up the Camshaft sensors................................................................ 45

9.12 Wiring up the Crankshaft sensor. .............................................................. 46
9.12.1 Ignition Timing Strategy .................................................................... 48
Initial timing + Basic advance angle + Corrective advance angle = Total spark advance.
......................................................................................................................... 48
9.13 - Wiring up the O2 Sensors (four?)............................................................ 48
9.13.1 ... four o2's / some engine ................................................................. 49

9.13.2 Two o2 sensors operating as four........................................................ 49
9.14 - Wiring up the Injectors .......................................................................... 50
9.14.1 1uzfe injectors. ................................................................................. 50

9.14.2 Random fuel and Injector information. ................................................ 51
9.14.3 Injector Configurations ...................................................................... 54
9.15 How to test the injectors .......................................................................... 55

9.16 The Fuel Regulator & Pulsation Dampener .................................................. 55
9.17 Wiring up the ECU to turn on. ................................................................... 59
9.18 Wiring up the Alternator. ......................................................................... 60
9.19 - Water Temp, Tacho and Pin Order in Plugs............................................... 63
10 Different Kinds of diagrams ......................................................................... 64
10.1 Toyota Diagrams..................................................................................... 65

10.2 The difference: ....................................................................................... 66
10.3 - Water Temp ......................................................................................... 66
11 Tacho and Igniters ..................................................................................... 67
11.1 Tacho .................................................................................................... 67

11.2 Igniters ................................................................................................. 68
11.3 Igniter Operation .................................................................................... 70
11.4 Spark Confirmation IGf ............................................................................ 71
12 Wiring the Surf Automatic to run with the 1uzfe ............................................. 71

13 - Diagnostic Codes OBD1 ............................................................................ 72
14 Connection Board for older cars / race cars ................................................... 75
15 - Swapping Between Series One and Series Two (non VVTI) engine ................. 77
16 Diagrams & Reference Material .................................................................... 78
17 1UZ-FE NON-VVTI - Diagrams ..................................................................... 81
17.1 - 1993 1uzfe Diagram .............................................................................. 81

17.2 - 1992 Celsior 1uzfe UCF11 Diagram ......................................................... 81
17.3 - UZS131 Diagram .................................................................................. 81
17.4 - 95'96 Lexus LS 400 Diagram (also works for 95,95 Crown Majesta) ............ 81
18 1UZ-FE VVTI - Diagrams ............................................................................. 81
18.1 - VVTI Engine Wiring Diagram .................................................................. 81

18.2 - VVTI Engine Wiring Diagram - LF1ECS98 ................................................. 81
18.3 - VVTI Engine Wiring Diagram - LF1EA98 ................................................... 81
18.4 - VVTI Engine Wiring Diagram - 1998 Crown Majesta .................................. 81
19 2UZ-FE - Diagrams..................................................................................... 81
20 3UZ-FE - Diagrams..................................................................................... 82
20.1 - 2000 - 2003 3UZ-FE Tundra Diagram ...................................................... 82
21 Links to Useful Sites ................................................................................... 82
21.1 - Phil Bradshaw's Home Page ................................................................... 82

21.2 - Lextreme's Forum (Wiring Section) ......................................................... 82
21.3 - v-eight.com Forum (Wiring Section) ........................................................ 82
1 Lets begin
Firstly congratulations on your purchase, it's a good motor, pretty famous. This
document originated in the forums of lextreme.com, it was then moved to
oldschool.co.nz where it was further developed.
I guess your reading this because you’re wiring it up with the factory ecu, or you want
some information on how to wire in an aftermarket ecu. Have a read, if you run into
trouble join the oldschool.co.nz forum and send me a message (pm). I don’t get alot of
messages these days, so I'm guessing the thread and this document pretty well covers
the topic.
If you have never done this before, you will have to learn new things to wire an
engine up. You will make mistakes, connect the wrong wires, feel lost.
You can learn this. You can get an engine running it doesn’t take special abilities just,
patience, time and knowledge. Here’s the knowledge, I’m sure you can make the time.
The patience is something your on your own with ... if you get overwhelmed take a
break come back to it. Take good notes as you go, it’s too much to remember. Go easy
on yourself it’s a big job and you won’t do in just one day, least not the first time.
I can do in four hours now, the first time it took me three weeks and I stuffed up alot of
things. A friend and I sometimes wire engines up together, it’s really helpful having
someone else around to check your work as you go. Look, this is not an intelligence
thing, it's a follow the process thing, if you can make toast and coffee you can do this.
There are a few odd rumours out there; I’ll take a stab at a couple of them now;
• EFI is too complex: fair enough, it is complex but it only takes thinking. It’s not
like ‘woman kind of complex’. It’s very learnable, for the most part it’s just
connecting wires together according to a map.
• It is generally not true that it takes 5 wires to connect up a 1uz, .. well .. not if
you want it run well.
• You can’t just ‘connect it all up’ it’s best to tidy up the loom and customize the
shape and configuration of the loom, for the car it's going into,
• They don’t run without the automatic gearbox: This is rubbish, its just a rumour.
• Tip: in order to run the engine in manual configuration, you'll remove quite a bit
of loom when cleaning out very little of that is actually the auto loom.
• Tip: don’t leave cut wires hanging around in the loom, seal them with a cap like
half on heat shrink that’s pressed closed.
• Terms:
o S1 = stage one on the key, this is normally called ACC.
o S2 = stage two, second position on the key. I often call this ‘switched
power’ normally called ‘IGN’
o S3 = Start, assumes Stage two is also live and stage one is not. Third
position on the key, momentary action.
o I’m fond of these terms; it’s easier for me not to abandon them.
2 Quick and Fast
2.1 - Quick and Dirty, this is what you connect + thoughts
2.1.1 In the ecu loom:

• +12V wired to pin (BATT)
• (M-REL) drives the Main EFI Relay: switches it on.
• (+B) and (+B1) both get 12volts when the Main EFI Relay is switched.
• Main EFI Relay appears to be working fine.
• (E11) is grounded.
• (STA) gets a 12volt input from starter relay when the engine is cranking.
• (IGSW) gets a switched power 12volts from the ignition switch.
• You might want to find the check light (W) and use as an earth for a light
(switched power on the other side), tells you if the ecu is on or not.
2.1.2 In the wiring loom:

• Find the injector power wire, and connect that to relay / switched power. It’s
usually a striped wire. In the older motors it’s Black/Orange, newer engines it’s
Blue/Red.
• Find the power to the igniters, connect that to a relay / switched power, usually
the same colour as the injector power wire.
• Sometimes: the sensor power wire is loose in the loom, find it, give it switched
power.
2.1.3 Neutral Start Switch

If the loom is in factory condition, and your running the auto this wire connects to the
shifter so you need to interact with it. The wire contains 12v+ in neutral.
2.1.4 Cold Start Injector

One installer commented;
"i cant see toyota doing something so silly relying on cold start injector :every
1uz I’ve done (500) ... I've never seen this and I’ve seen many 1uzs with no cold
start injector connected and they still start 90% perfect the cold start makes it
start that 10% better"
He's actually wrong, I've seen a very early (1989) quad cam 1uz-fe engine that has a
huge cold start injector under the upper inlet manifold, and it used it. The motor would
not start without the injector, at least on the ecu which came with it. The thing was
massive, it was like a 800c injector big silver metal thing, with a fuel line off the drivers
side billet fuel rail.

"if the ecu relied on coolant temp and throttle and all the other minor sensors then
u will never get in limp mode the engine will just turn off that’s why the ecu has
limp mode features this is so if the not so important sensors fail u can still drive
home there is no way anything (just for start) can be temp related otherwise u will
get problems, with the above rule."
He’s dead right, you can run a motor with hardly any sensors, including the temp
sensors, but bear in mind the ECU’s water temp sensor sets injector and timing
parameters, expected reduced power and possible fouling of the plugs.
2.2 Anti-Flooding Feature

"nearly all Toyota ecus have a built in safety so it doesn’t flood cylinders now the
igniters send a signal back to the ecu saying yes we have fired the spark plugs so
now u can fire the injectors. This is so if there is no spark the injectors will not
keep pulsing and flood the cylinders so basically u need spark before u get
injection but the ecu will pulse the injector once or twice right at the start of the
crank to get engine to start and if it doesn’t get a signal from the igniters after the
1 or 2 pulses of the injectors it then shuts the injectors down"
I have nothing to add to that.
2.3 Just to get it running

"now u have to realise the engine only needs few sensors to run. i don’t know why
people have this idea that everything needs to be connected for it to just start?
crank and cam and igniters are probably the only thing u need just to start engine,
TPS would help. it might run funny but it should start"
He’s dead right. You don’t need much to make the engine run. I really don’t have
anything to add on this, I’d only repeat what he wrote.
2.4 - The Method: this is how you wire up an engine.
The method for wiring up the engine, when I do it, is a blend of the quick and dirty
method. And what follows below when I get into it. Usually I start by noting the colours
of the EFI and igniters wires and then I pull on them, to find them in the loom.
I then look over the ecu, and note the wire’s I’m familiar with. I mark them using
masking tape (because it’s the only tape which works), and put a question mark at the
end of my note. So if I write B1 and I’m not 100% certain it’s B1, I put ‘B1 ?’.
Once I’m done playing guessing games I find a diagram which matches the engine.
Sometimes I can get pretty far just on guessing. I rarely ever complete a wire up on
guessing, you really will need a diagram which matches the engine. The method for
finding one is to either get lucky and find the right one, or find diagrams and attempt to
match them to the ecu.
2.4.1 The Method for counting the pins is:

Count the pins on the ecu with a pointer like a jewellery screw driver use the numbers
on the plugs to help with that. Match those numbers to the numbers for plugs in the
diagram, the pin tables and those code letters. Also, you need to match what you’re
seeing on the ECU and its plugs to the diagram you have and the engines loom, make
sure its all connected how it should be. As it happens the ECU plug and the diagram
exert match perfectly.
This is the 4th plug on a 1992 Celsior ecu, there are only five, six wires left once the
install is completed. The little red circles show you the location of the pin numbers. Some
plugs are counted right to left, and other plugs left to right. Some pins are blank from
factory. Sometimes there is only one number on a row. I find counting the pin locations
out quite frustrating sometimes.
The method is, go wire by wire, connecting what needs to be connected. Use the
diagram as a reference. I read off the pin locations by counting them in the plugs using
the numbers and plug locations, when I have a correct diagram for the engine which I
can trust this is an easy job. When I don’t, and this does happen from time to time, I
have to trace the wire back to its final location on the engine. This is done by removing
all the plastic casings, tape, etc. And the pulling on the cable from the ecu end, it will
tension in the loom, then you can find it further up and repeat. It sounds stupid but as
long as you’re gentle it’s very effective.
2.4.2 Get it right: this is no time for mistakes

You cannot afford to make a single mistake. So don’t. You need to know that you did can
be trusted, which means when it doesn’t start or something is wrong later you can trust
the work you have done in an arrogant sort of (time saving) sense. When it's not
obvious you need to think about the wire. i.e. where is that going?, is it needed? (re:
auto vs manual trans).
Be brutal, remove what you don’t need and connect the important wires, as you locate
them or at least mark them (I use masking tape and a fine permanent marker). Don’t
just find them, then forget about them. If you work carefully, and in a focused way, you
will have no trouble completing the task. If your all over the place and scattered, this
thing will be hard to finish.
Starter Wire (second largest black wire) should really be on the other side of an 80amp
relay, tripped of the ignition key. Remove the plugs that don’t plug into the ecu any
wires obviously of no use, etc, with care. (E.g. the 1UZ-FE donor cars dash plugs)
As you go join your wires to the 'new' cars loom, or a custom board, or whatever suits,
you pick. You should really / it is good practise too add fuses to some parts of the loom
here is a good list to start with:
• An 80 fuse on the main line supplying the relays (constant power)

• The switched power to the alternator
• The constant power to the alternator
• ECU switched power, and ecu memory (BATT)
If it's an older car, and the wiring is 'old' put a fuse between the relays and the key (why
trust the key not to short out) eg. the wire that trips the relays like the coil relay and the
relays the sensor's power is on. Wouldn’t hurt to put a fuse between the check engine
light and power, fuses are cheaper than lights: but you really don’t need too.
• 'dot' the corners on the lex diagrams makes them easier to read
• take good notes as you go, to stop re-work, and make diagnostic easier
• If you do careful, thoughtful work you can trust it.
2.4.3 Do you need four relays ?

• One for Starter solenoid wire. (travels with Knock Sensors @ rear water bridge
plug) 80amp relay best.
• One for Injectors (all alone). switched on S2/IGN on while S3/Start key position
• One for the Coils and igniters (all alone).. switched on S2/IGN on while S3/Start
key position
• One for the fuel pump. (MREL) a ECU pin that is switched on S2/IGN on while
S3/Start key position but off when engine not running (5sec delay ?) - i.e. stops
fuels pumps in a crash.
2.4.4 A few fuses too,

• The sensor wire power, probably two separate wires, or more fuse each one.
• put 10amps on the o2 heater wires if it's a four o2 model engine,
• Around 7amps for any other sensor power wires.
• I like to fuse the ecu’s power supply as a good practice thing. It has thermal
fuses in it though.
2.4.5 The dash plug in the ecu’s end of the bundle.

So once you've done every wire on the ECU, turn to the ones linked to the dash plugs.
The plugs which do not plug into the ecu contain the main sensor power wire, which is
usually a striped wire, same colour as the injector and igniters power wire. There is also
the oil (idiot) light, the water temp (dash) and a few other thing in there. Often there are
two, one is white, the other is grey. I think it’s the white one which is for the dash.
2.4.6 You will need to add in a plug

You will need to install a plug into the engines wiring harness to take the input wires,
and the output wires. The input wires are things like the injector power feed, the igniters
power feed, the starter solenoid wire. The output wires are things like water temp, oil
temp or pressure, etc.
I have been down the track of purchasing plugs for electronic stores and high quality
ones from suppliers at high costs. I strongly suggest going to a wreakers yard and
cutting a high quality plugs from under the dash of a late model cars. I prefer Euro’s
because the plugs are worth around $100 each new, but a Japanese car is fine. A 10 pin
plug will be fine, along with a very heavy duty single pin plug for the starter solenoid
cable. I sometimes install a second plug, rather than doubling up the usage. I use the
second plug for low current things like the check engine light (W) and water temp, and
such.
2.4.7 Important to get the Check Light Running ASAP

• As soon as you can, get the check engine light running,
• When the ECU is on, it should stay solid, and blink when diagnostic mode is
entered.
• The PIN 'W' is the earth connection usually a small plug like a 16 pin one,
• The power is switched (S2) or (IGN) on the key,
• Get the other wire for the light (small 12v light) on that,
• It will take a moment to light up, or blink.
2.4.8 The ECU must be ok for the light to blink

It’s a NOT good sign but if won’t run and everything’s wired up right. The ECU could be
damaged, it must at least flash the check light when powered up right. When in
diagnostic mode (TEI and E1 pinned out on diagnostic plug or connected via a switch or
manually).
I’ve yet to see an install that does not produce one or two check codes, (FC and FCR not
connected for example), there always be a code to pull, make it your mission to get that
working first. So you know the ecu is ok, on (most important), and working because it
doesn't follow that the ECU is undamaged until it 'actually' runs (the motor) and/or
produces codes. To engage the ecu’s diagnostic mode connect TE1 and E1 [E1=engine
earth]. W acts as earth for the light, and switched power on the other side of the light.
2.4.9 Your motor do it your way.

Look it’s your motor, do it your way. It’s not for me to tell you what you should or
shouldn’t do. If you want to use crimpable joins and speaker wire to connect it up go for
it, .. um .. it might randomly stop running at some point, but your welcome to try it. I
like to seal up Toyota’s joins by re-doing with solider and heat shrink, that’s because I’m
kind of anal retentive. I like to get my wire from the looms of wreaked cars because it’s
high quality and cheap. I never use crimp able joins, I can solider. You don’t ‘have’ to do
it my way, do it the way that makes the most sense for you in your situation.
I like to make sure the heat shrink well exceeds the join great for the 4x4 and hilux guys
/ off road people to seal the loom for water and mud immersion and for jet boaters.
If you’re doing this for a client: respect their budget.

Who wants to save a buck, reduce the work load and leave plugs in like the old dash
plugs, and the diagnostic plug, tidy coiled and taped, nicely done. I seal up lose wires by
capping them with heat shrink and cable tie / tape them to the main loom. Description’s
on masking tape which seems to last the best.
If you’re doing this for a client: do a good job.

The ecu should be free of codes if possible: some codes are no problem like 78, 14, 34,
35, 71, 42. But others are a huge issue. It must not be in the default map mode/limp
when done, if it is then the job is not completed. As noted before it is best to join wires
with generous amounts of heat-shrink either side, and use solider, or better. Not crimp-
able joiners. It's an engine not a car stereo.
Take some pride in your work, and yourself. If you can wire a motor up that’s specialist
knowledge which is transferable to EVERY other kind of engine that’s something to be
proud of.
2.5 - Toyota wiring follows a certain kind of logic,

Toyota wiring follows a certain kind of logic, here is that key to that logic. Each pin
usually does something; it’s not always something important. You can just de-pin or
remove the auto trans by snipping the wires. A few pins are sometimes blank across
various engines as various things are there or not, but the core stuff is always there, like
crank sensors (which sense where the motor is in its revolution), and the two cam
sensors in each head, injectors. The motor does not always need everything else to run:
to run well it would, but not to just 'run'. I think to think about the sensors like this: they
are all just resistors (not totally true). Some are VITAL, some are just needed, and some
are not even needed.
2.5.1 Primary Sensors

• Crank Sensor, (NE)
• Cam Sensors (both of them G1 and G2)
• ... the engine's ecu will not even think about starting without these.
2.5.2 Secondary Sensors

• Air Temp (in the MAF or AFM),
• Air Volume sensor,
• ECU water temp sensor,
• O2 sensors (primary or sub),
• TPS
• Fuel pressure sensor (in fact I dont think this even returns an error most of the
time)
• ... the engine's ecu will allow it to run, but will return an error and fall into limp
mode; but still run just fine.
2.6 Missing the fourth plug ? a Dirty fix.

You don't need plugs for the ecu. There are ways around the problem. You may
run separate pins in shrink tubing. You can just can extract pins from a broken
harness that is usually available at wreckers for nothing. Or pins can be bought in
electronic components store. BLS series fit ok.
He's Dead right, you can just de-pin some random ecu plug and as long as those pins fit
well, you can then put heat shrink over them and pin them up onto the ecu. that would
work well if your short the 4th plug that many people often find missing. Recently had a
late night phone call from a guy that lives about 400km's away from me, (he's here on
this forum) he was missing the fourth plug that traces off to things like constant power,
and switched power, that one ends up having like 4-5 pins used.
He did exactly this, in fact he de-pinned un-needed stuff from other pins and used those
pins to get it up and running. Fact is, apply enough hot glue/silicone and you pretty
much have a plug when it dries. (ok, that is well dodgy though) He runs this plug still,
five months later he said 'you wouldn't want to remove it from the ecu but damn it all, it
works just fine.
3 The Pin & Acronyms
Below in the section is some really important information. The description column
matches up to the tiny little codes under the circled letters in the factory diagram same
with the lex extreme diagrams, those codes Like 'G+' all mean something, for example
THW is water temp, etc. The last column, details how a 96 motor was converted from
Automatic, to manual, you, can also used that information in relation to the letter codes,
and whether or not they were used to assist and help converting other year 1uz's,
perhaps other engines too.
The following ‘pin tables’ and the order of them the plug numbers and pin locations are specific to a
particular ecu. This is not a ‘how to’ this is a description of specific wires. Unless your engine matches
these tables in which case you’re really lucky and have at it.
3.1 The factory diagrams

The factory diagrams spread the plug letters, and the pin numbers all over the place,
making them hard to read and work with. It doesn’t matter what letter the plugs
are/use, whether it’s a four plug 92 onwards, or two huge 40 pin ones, or three (old
school majestic) ECU, the description column still applies to the function it performs. Up
to the point VVT-i came along, and the OBD2 code system (1997?), in which case there
are a few additions but the below information is still very helpful.
It's a head - ache trying to read them when you’re working with them, highlighters help,
use the pins to guide your work and they will tell what each letter code means and does,
the information below should help you work any diagram, because every DECENT
DIAGRAM *cough* has those on it.
3.2 Using the letter codes below

The tables below are useful for wiring up any Toyota engine. These codes are common
wires for the most part, each 1UZ-FE engine is wiring up using codes like THW and STA,
to explain what a pin on the ECU is doing,
When you have the correct diagram for your engine, these codes and the explanations of
them below. You can go off; wire up an engine knowing what each pin does by referring
to this. Once you start you'll see what I'm explaining is actually quite easy, and time
consuming. It takes me hours to trace, and mark all the wires, it takes me hours to
connect everything up after I'd done that, it’s kind of boring work actually.
NOTE: the long description for pin 1 (FPR) is correct the output is 0.004 volts which is
too low to trip a relay. Ideally you want the ecu to turn the pump(s) on and off
depending on whether or not the engine is running. If you have a crash you want the
pump(s) to stop. This is the pin you do that from, but the output is too low to do that,
you need the Fuel Pump Controller to do this.
4 Pin Functions.
4.1 16 pin
The order of this information, it’s plug numbers and pin number are specific to a particular ecu.
Pin Descrip Long Description Used / Or Not

1 FPR output is actually 0.004 volts to low to trip a NO
relay.
2 THG Deleted EGR Gas Temp Sensor NO
3 W Check Engine Light (pin 10) on Custom Plug YES
One
4 FC Fuel Pump controller No
5 TE1 Spliced to (pin 12) on Custom Plug One YES
6 OIL Traces into Auto Loom / Oil Temp Auto In place
7 KNK1 Top left Knock Sensor YES
8 PGR1 Pin 1 Evap Valve Left Side Engine NO
9 PR Pin 1 Fuel Pressure Control Valve NO
10 THW0 Off into Air Conditioning Loom NO
11 KNK2 Top Centre Knock Sensor YES
12 L (+) Gear Selector Indicator (Low) (Auto) In Place
13 2 (+) Gear Selector Indicator (2nd) (Auto) In Place
14 R (+) Gear Selector Indicator (R) (Auto) In Place
15 EO3 Earth Right Side Head YES
16 E1 Earth In Common YES
- both O2’s (the working ones)
- Data Link E1
- Sheilding to Both Camshaft Sensors
• (Core Wire: A must connect)

o The engine will not run without this wire.
• (Core Wire: B must connect eventually)
o The engine will run without this wire, but in default map. You should sort
this out.
• (NOT A Core Wire)
o The engine will run without this wire, perhaps not with the Automatic
Gearbox, with a manual you don’t need this.
Note: it makes me uncomfortable to not say this: TPS and the o2's do need to be there
for it to run well, so does the MAF, the Idle Control stepper motor, etc. But, it'll start and
run without them (MAF is questionable with some models).
4.1.1 FPR Fuel Pump Relay,

... (NOT A Core Wire) –FPR - Across Fuel Pump Relay, - this does not trip a relay, the
output I measured today was 0.004 volts not enough to trip a normal relay.

FPC/FPR would control fuel pump computer. They are to be inspected with
oscilloscope, you will find 5v pwm signal there. There are ways of setting these
outputs to control your pump without stock fuel computer
An uncomfortable error: One guy emailed me saying:

I wired the FPR (Pin1 on 16pin connector) trigger into the fuel relay which was
fine in the event truck had an accident or stalled fuel relay is shut down. However
I had also wired in the FC (Pin 4 on 16 pin connector) trigger in the circuit open
relay thinking that the "Fuel Controller" was required, by only having a single
speed pump in the hilux when the ecu triggered FC in theory to by pass the
resistor and pump at high speed i was in fact cutting out the fuel pump
completely. Only an issue when under load.... and when is a 1uz fe not under
load?? you would have to be a nanna. Trick for young or not so young wannabe
car conversion experts like myself. Hence the reason it would rev slowly up to
6500 rpm but when punched – Death
Mistakes are easy to make. I think it’s best to leave all the marking (masking tape)
identifiers on the wires until your sure it’s all running just fine.
4.1.2 THG Gas Temp Sensor

... (NOT A Core Wire) - THG Deleted EGR Gas Temp Sensor - this is normally in the body
loom with the extra o2's sensors that are located after the Cat-converter. Rare to get
this sensor. No a needed sensor, motor runs fine without it,
4.1.3 W Check Engine Light
... (NOT A Core Wire) - W Check Engine Light - this is an earth wire. Apply power from
stage two on the key (IGN) second position, to the other side of a 12v light using W as
the earth for the light. this will give you a check engine light. When you earth out TE1 to
the engine this light will flash and give you codes (refer to diagnostic how too for more
information)
4.1.4 FC Fuel Pump controller

... (NOT A Core Wire) - FC Fuel Pump controller - you dont need this wire, this is 'half
the speed wire' it sends a signal to the fuel controller ECU to half the pumps speed at
idle, this does not trip a relay, the output I measured today was 0.005 or 0.003 volts not
enough to trip a normal relay.
4.1.5 TE1 - diagnostic

... (NOT A Core Wire) - TE1 TE1 is the diagnostic switch in the ECU, earth this out and
the ECU goes into diagnostic mode,
4.1.6 OIL Auto Oil Temp sensor

... (NOT A Core Wire) - OIL Traces into Auto Loom / this is the Oil Temp sensor wire for
the Automatic transmission - you dont need to use this wire,- I connect this when
running the auto
4.1.7 KNK1 Top left Knock Sensor

... (Core Wire:B must connect eventually) - KNK1 Top left Knock Sensor - there are two
knock sensors in the engine's valley. You need both there, they are not known to fail,
4.1.8 PGR1 Evap Valve

... (NOT A Core Wire) - PGR1 Evap Valve Left Side Engine,
4.1.9 PR Fuel Pressure Control Valve,

... (NOT A Core Wire) – PR Fuel Pressure Control Valve,
4.1.10 THW0 Air Conditioning

... (NOT A Core Wire) - THW0 goes into the Air Conditioning Loom,
4.1.11 KNK2 Top Center Knock Sensor,

... (Core Wire:B must connect eventually) - KNK2 Top Center Knock Sensor,
4.1.12 L(+)Gear Selector Indicator (Low)

... (NOT A Core Wire) - L(+) Gear Selector Indicator (Low) (Auto) Use if running the
Automatic Gearbox through the 1uz ecu, otherwise delete,
4.1.13 2(+) Gear Selector Indicator (2nd)
... (NOT A Core Wire) - 2(+) Gear Selector Indicator (2nd) (Auto) Use if running the
4.1.14 R(+)Gear Selector Indicator (Reverse)

... (NOT A Core Wire) - R(+) Gear Selector Indicator (Reverse) (Auto) Use if running the
4.1.15 EO3 Earth Right Side Head,

... (NOT A Core Wire) - EO3 Earth Right Side Head,
4.1.16 E1 Earth In Common,

... (Core Wire:A must connect) -E1 Earth In Common, - to be clear: from the pin/plug
this wire connects to the earth wire E1 which terminates on the (engine?: One of the
cylinder heads) so .. any old earth will do, the correct one is best.
... - both O2’s (include the rear two if you have four o2's),
... - Data Link E1,
... - Sheilding to Both Camshaft Sensors.
4.2 22 Pin

1 VC TPS – pin 4 YES
2 NCO(+) Over drive direct clutch speed sensor (AUTO) No
3 NCO(-) Over drive direct clutch speed sensor (AUTO) no
4 SP2 (-) Speed Sensor no
5 NE(+) Crank - tested - connected YES
6 NE(-) Crank - tested – connected YES
7 VTA1 TPS pin 3 YES
8 VG Mass Air Flow Meter Pin 2 YES
9 SP2(+) Speed Sensor YES
10 G1(+) Pin 1 Camshaft position sensor left bank YES
11 G1(-) Pin 2 Camshaft position sensor left bank YES
12 VTA2 Traction Control – pin 4 sub TPS NO
13 OXL1 Pin 3 left O2 sensor YES
14 HTR1 O2 sensor pin 1 – (right) YES
15 HTL1 O2 sensor pin 2 – (Left) YES
16 G2(+) Pin 1 right camshaft sensor YES
17 G2(ES) Pin 2 Crankshaft position sensor (shared in YES
common with NE
18 THA Mass Air Flow Meter Pin 3 (checked out ok) YES
19 OXR1 Right O2 sensor pin 3 YES
20 THW Engine Coolant Temp Sensor right front pin 2 YES
21 EVG Pin 5 Mass Air Flow meter YES
22 E2 Common Sensor Earth YES
- Mass Air
- ERG
- the 34pin plug, on pin 31
- engine coolant temp
- sub (traction control) throttle
- TPS pin 1
- Vapor Pressure Sensor
Break down of the codes above.
4.2.1 VC TPS – pin 4,

... (Core Wire:B must connect eventually) - VC TPS – pin 4,
4.2.2 NCO(+)Over drive direct clutch speed sensor

... (NOT A Core Wire) - NCO(+) Over drive direct clutch speed sensor (AUTO), - I dont
connect this unless running the auto
4.2.3 NCO(-) Over drive direct clutch speed sensor

... (NOT A Core Wire) - NCO(-) Over drive direct clutch speed sensor (AUTO), - I dont
connect this unless running the auto
4.2.4 SP2 (-)Speed Sensor

... (NOT A Core Wire) - SP2 (-) Speed Sensor, - I dont connect this unless running the
auto
4.2.5 NE(+) Crank Sensor

... (Core Wire:A must connect) - NE(+) Crank - test - connect,
4.2.6 NE(-)Crank Sensor

... (Core Wire:A must connect) - NE(-) Crank - test – connect,
4.2.7 VTA1 TPS pin 3,

... (Core Wire:B must connect eventually) - VTA1 TPS pin 3,
4.2.8 VG Mass Air Flow Meter Pin 2,
... (Core Wire:B must connect eventually) - VG Mass Air Flow Meter Pin 2,
4.2.9 SP2(+) Speed Sensor

... (NOT A Core Wire) - SP2(+)Speed Sensor, - I dont connect this unless running the
auto
4.2.10 G1(+) Camshaft position sensor left bank,

... (Core Wire:A must connect) -G1(+) Pin 1 Camshaft position sensor left bank,
4.2.11 G1(-) Camshaft position sensor left bank,

... (Core Wire:A must connect) -G1(-) Pin 2 Camshaft position sensor left bank,
4.2.12 VTA2 Traction Control – pin 4 sub TPS

... (NOT A Core Wire) - VTA2 Traction Control – pin 4 sub TPS
4.2.13 OXL1 left O2 sensor

... (Core Wire:B must connect eventually) - OXL1 Pin 3 left O2 sensor,
4.2.14 HTR1 O2 sensor pin 1 – (right),

... (Core Wire:B must connect eventually) - HTR1 O2 sensor pin 1 – (right),
4.2.15 HTL1 O2 sensor pin 2 – (Left),

... (Core Wire:B must connect eventually) - HTL1 O2 sensor pin 2 – (Left),
4.2.16 G2(+) right camshaft sensor,

... (Core Wire:A must connect) - G2(+) Pin 1 right camshaft sensor,
4.2.17 G2(ES) right camshaft sensor,

... (Core Wire:A must connect) - G2(ES) Pin 2 Crankshaft position sensor (shared in
common with NE),
4.2.18 THA – Air Temp (AFM/MAF Pin 3)

... (Core Wire:B must connect eventually) - THA Mass Air Flow Meter Pin 3 (checked out
ok),
4.2.19 OXR1 Right O2 sensor

... (Core Wire:B must connect eventually) - OXR1 Right O2 sensor pin 3,
4.2.20 THW Coolant Temp Sensor

... (Core Wire:B must connect eventually) - THW Engine Coolant Temp Sensor right front
pin 2,
4.2.21 EVG Mass Air Flow meter
... (Core Wire:B must connect eventually) - EVG Pin 5 Mass Air Flow meter,
4.2.22 E2 Common Sensor Earth,

... (Core Wire:A must connect) - E2 Common Sensor Earth, NOT the same as E1,this is
the sensor earth common wire, it is used only by sensors and must NOT be earthed to
the engine, if you do that the signal noise will be so high the engine will run poorly at
random places, it will over fuel, and under fuel
... - Mass Air,
... - ERG,
... - the 34pin plug, on pin 31,
... - engine coolant temp,
... - sub (traction control) throttle ,
... - TPS pin 1,
... - Vapor Pressure Sensor YES
4.3 28 Pin

1 HTR2 Heated o2 (bank2) no
2 OXR2 O2 sensor not in loom No
3 OXL2 O2 sensor not in loom No
4 HTL2 O2 sensor not in loom No
5 PWR (-) Stops starting when not in park No
6 PWRL(+) Return signal for the above No
7 ODI Cruise Control (not blank) No
8 AD No pin in place No
9 IGSW To ECU - turns it on (stage 2 on key) YES
10 SDL Data Link connector No
11 SEL O2 sensor not in loom No
12 SPDM Speedo Signal (output from Ecu No
13 ACMG Air Conditioning No
14 BATT ECU constant pwr supply (memory) YES
15 ELS No
16 BK No
17 TPC Vapor Pressure sensor No
18 PTNK Vapor Pressure sensor No
19 L1 Electronic Suspention (none in place) No
20 AC For AC No
21 NEO For Anti Lock Brakes No
22 +B ECU switched power (same circuit as IGSW) YES
23 N/A Blank No
24 MREL EFI Relay (turn on) YES
25 EFI (-) Anti Lock Breaks No
26 EFI (+) Anti Lock Breaks No
27 TRA Anti Lock Breaks No
28 3 Auto Trans (3) Light No
Break down of the codes above
4.3.1 HTR2 O2 Sensor Sub Right

... (Core Wire:B must connect eventually) - HTR2 Heated o2 (bank2) Right one
4.3.2 OXR2 O2 Sensor Sub Right

... (Core Wire:B must connect eventually) - OXR2 O2 sensor Right secondary one,
4.3.3 OXL2 O2 Sensor Sub Right

... (Core Wire:B must connect eventually) - OXL2 O2 sensor Right secondary one,
4.3.4 HTL2 O2 Sensor Sub Left

... (Core Wire:B must connect eventually) - HTL2 O2 sensor Left secondary one,
4.3.5 PWR (-) Stops starting when not in park

... (NOT A Core Wire) - PWR (-) Stops starting when not in park,- I dont connect this
unless running the auto
4.3.6 PWRL(+) Return signal for the above

... (NOT A Core Wire) - PWRL(+) Return signal for the above, - I dont connect this
4.3.7 ODI Cruise Control

... (NOT A Core Wire) - ODI Cruise Control (not blank),
4.3.8 AD
... (NOT A Core Wire) - AD No pin in place,
4.3.9 IGSW – Turns Ecu on.
... (Core Wire:A must connect) -IGSW To ECU - turns it on (stage 2 on key) this the
wire that takes 12+ to the ECU to turn it on.,
4.3.10 SDL Data Link connector

... (NOT A Core Wire) - SDL Data Link connector - I usually de-pin this wire,
4.3.11 SEL O2 sensor secondary

... (Core Wire:B must connect eventually) - SEL O2 sensor wire (secondary)
4.3.12 SPDM Speedo Signal

... (NOT A Core Wire) - SPDM Speedo Signal (output from Ecu) - I dont connect this
4.3.13 ACMG Air Conditioning

... (NOT A Core Wire) - ACMG Air Conditioning, is this the fast idle wire ?
4.3.14 BATT - ECU constant pwr supply

... (Core Wire:A must connect) -BATT ECU constant pwr supply (memory) use this, dont
put it too switched power.
... The 1uz ecu learns, it needs memory / constant power in the ECU to store what it
learns. Reset the ECU by disconnecting this wire.
4.3.15 ELS
... (NOT A Core Wire) - ELS no notes on this.
4.3.16 BK
... (NOT A Core Wire) - BK No notes on this,
4.3.17 TPC - Vapour Pressure sensor

... (NOT A Core Wire) - TPC Vapour Pressure sensor,
4.3.18 PTNK Vapour Pressure sensor

... (NOT A Core Wire) - PTNK Vapour Pressure sensor,
4.3.19 L1 Electronic Suspension,

... (NOT A Core Wire) - L1 Electronic Suspension,
4.3.20 AC - Air Conditioning

... (NOT A Core Wire) - AC For AC: is this? the wire the puts the fast idle mode into place
? - I think it is
4.3.21 NEO - Anti Lock Brakes,

... (NOT A Core Wire) - NEO For Anti Lock Brakes,
4.3.22 +B - ECU switched power
... (Core Wire:A must connect) -+B ECU switched power (same circuit as IGSW),
4.3.23 n/a
...blank..
4.3.24 MREL - EFI Relay (turn on)

... (NOT A Core Wire) – MREL EFI Relay (turn on) - this wire comes from an ECU PIN and
it goes ro (12+) the EFI replay to turn it on,
... e.g. the relay that provides power to the injectors (only) - turns off when engine not
running, I always use this for safety reasons.
4.3.25 EFI (-) - Anti Lock Breaks,

... (NOT A Core Wire) - EFI (-) Anti Lock Breaks,
4.3.26 EFI (+) - Anti Lock Breaks,

... (NOT A Core Wire) - EFI (+) Anti Lock Breaks,
4.3.27 TRA - Anti Lock Breaks,

... (NOT A Core Wire) - TRA Anti Lock Breaks,
4.3.28 3 - Auto Trans (3) Light

... (NOT A Core Wire) - 3 Auto Trans (3) Light, - I dont connect this unless running the
auto
4.4 34 Pin Plug


1 SLN + (Auto) Electric Solenoid #4 No
2 SLU + (Auto) Electric Solenoid #3 No
3 SLN - (Auto) Electric Solenoid #4 No
4 SLU - (Auto) Electric Solenoid #3 no
5 #60 Injector 6 Earth / ECU fires injector from this YES
11 S1 (Auto) Electric Solenoid #1 No
12 IGF1 5 Pin Ignitor pin 1 (on that plug) YES
13 STA Tells Ecu engine is being started YES
14 NSW Tells Ecu engine is being started YES
17 S2 (Auto) Electric Solenoid #2 YES
18 BLANK Not in use -
19 BLANK Not in use -
20 ISC4 Pin (3) Idle Control Valve YES
24 IGT1 5 Pin Ignitor pin 2 (on that plug) YES
25 IGT2 4 Pin Ignitor pin 2 (on that plug) YES
26 IGF2 4 Pin Ignitor pin 1 (on that plug) YES
27 EGR4 EGR Valve (this is blank) -
31 IDL2 Pin 1 – Idle (cut out as used in traction cntrl) NO
32 IDL1 TPS - Pin 2 YES
33 E02 Earth Left Rear Cylinder Head YES
34 EO1 Earth Left Rear Cylinder Head YES
4.4.1 SLN + (Auto) Electric Solenoid #4

Break down of the codes above
... (NOT A Core Wire) - SLN + (Auto) Electric Solenoid #4, - I don’t connect this unless
running the auto
4.4.2 SLU + (Auto) Electric Solenoid #3

... (NOT A Core Wire) - SLU + (Auto) Electric Solenoid #3, - I don’t connect this unless
running the auto
4.4.3 SLN - (Auto) Electric Solenoid #4

... (NOT A Core Wire) - SLN - (Auto) Electric Solenoid #4, - I don’t connect this unless
running the auto
4.4.4 SLU - (Auto) Electric Solenoid #3

... (NOT A Core Wire) - SLU - (Auto) Electric Solenoid #3, - I don’t connect this unless
running the auto
4.4.5 #60 Injector 6
... (Core Wire: A must connect) -#60 Injector 6 Earth / ECU fires injector from this by
earthing out the wire,




4.4.10 #10 Injector 1

4.4.11 S1 - (Auto) Electric Solenoid #1

... (NOT A Core Wire) - S1 (Auto) Electric Solenoid #1, - I don’t connect this unless
running the auto
4.4.12 IGF1 Igniter

... (Core Wire: A must connect) -IGF1 5 Pin Igniter pin 1 (on that plug),
4.4.13 STA - Tells Ecu engine is being started

... (Core Wire: A must connect) -STA Tells Ecu engine is being started - connect this wire
to the start relay output, or the black starter SOLENOID wire, not the main cable.
... It must have power, when the engine turning over and starting (if not power, no start
/ couple of fires that’s it).
One Installer Wrote

I would strongly recommend too connect STA/NSW pins as per Toyota diagram.
Though the engine starts without both of them connected just as fine.
However, I strongly disagree. I'm sure that STA is the pin that tells the engine that it's
being turned over, and without it, the ECU has no idea it's being started. (In my humble
opinion). Furthermore I'm sure that NSW must have 12v+ on it, otherwise the engine
thinks the Automatic gearbox is in drive, so it refuses to fire at all. However, I am not
always correct and if I have a dissenting opinion available I will offer it.
4.4.14 NSW - Neutral Start Switch

... (Core Wire:A must connect / deal with.) -NSW Neutral Start Switch: has 12+ when in
neutral - pair with 'STA' wire so 12v+ is present during starting, in a manual conversion,
if your running the (factory) auto and the auto loom is present in factory condition the
NSW tail out of the loom (near the plugs and NOT part of the auto loom) is meant for the
dash display DO NOT connect that to +12v it WILL prevent starting completely, engine
wont even fire (more than once) –
4.4.15 #80 Injector 8

... (Core Wire:A must connect) -#80 Injector 8 Earth / ECU fires injector from this by
4.4.16 #70 Injector 7

... (Core Wire:A must connect) -#70 Injector 7 Earth / ECU fires injector from this by
4.4.17 S2 - (Auto) Electric Solenoid #2

... (NOT A Core Wire) - S2(Auto) Electric Solenoid #2 - I dont connect this unless
running the auto,
4.4.18 Blank
... blank...
4.4.19 Blank
... blank...
4.4.20 ISC4 - Idle Control Valve

... (Core Wire:B must connect eventually) - ISC4 Pin (3) Idle Control Valve,
4.4.21 ISC3- Idle Control Valve


4.4.24 IGT1 Ignitor

... (Core Wire:A must connect) - IGT1 5 Pin Ignitor pin 2 (on that plug),
4.4.25 IGT1 Ignitor

... (Core Wire:A must connect) - IGT1 4 Pin Ignitor pin 2 (on that plug),
4.4.26 IGF2 Ignitor

... (Core Wire:A must connect) - IGF2 4 Pin Ignitor pin 1 (on that plug),
4.4.27 EGR4 - EGR Valve

... (NOT A Core Wire) - EGR4 EGR Valve - ,
4.4.28 EGR3 - EGR Valve

4.4.29 EGR2- EGR Valve

... (NOT A Core Wire) - EGR2 EGR Valve -,
4.4.30 EGR1- EGR Valve

4.4.31 IDL2 - traction control system

... (NOT A Core Wire) - IDL2Pin 1 – Idle This is used by the traction control system, I
ignore/remove it,
4.4.32 IDL1 - TPS

... (Core Wire:B must connect eventually) - IDL1 TPS - Pin 2,
4.4.33 E02 - Earth Left Rear Cylinder Head

... (Core Wire:A must connect) -E02 Earth Left Rear Cylinder Head
... (there is an earth point on each head at the back, under the plastic cam end seal, I
use these earth points, both of them.
4.4.34 EO1 - Earth Left Rear Cylinder Head.

... (Core Wire:A must connect) -EO1 Earth Left Rear Cylinder Head.
5 The ECU is a learning ecu

NOTE: the 1uz ecu's are learning ecu's, they learn as they go. It takes around 5mins for
the ecu to learn an engine, around 2-3wks for it to completely learn an engine (driving
conditions). disconnect your ECU from power and it will have to re-learn. That, can
sometimes be a very good thing, one client reported huge power gains after a reset due
to a prior fault which was fixed, but the ECU was not reset immediately afterwards.
When he did, .. like a new engine.
6 It wont start for no obvious reason

NOTE: when you go to start the engine up for the first time it might not even fire the
first time for no obvious reason. So, assuming your sure that nothing is wrong, the fuel
lines are the right way around, it has spark, the ecu is on and working then the problem
is you didnt crank it over enough, with enough throttle. Do that. Sometimes when you
start a motor it fires a couple of cylinders and falls over and stalls. Crank it over again.
Give it more throttle say start at 1/4 and ease it up while cranking it to 50%. If it
catches and falls over, repeat. If fires say a few cylinders, and they are on oposing banks
you've probably got stuck injectors. Tap them while applying 12v+ or soak them in fuel
and then tap them. Or take them out carefully and try not to wreak the o-ring at the top
or the seal at the bottom.
Or try starting it again, which is what I did today (27/11/2011) with a customer’s car, it
was catching enough cylinders to run perhaps 3 cylinders at most. I could hear
everything was ok, it just wasn't firing on all 8. I knew I could trust my work I’d been
very careful and things had gone really well, right diagram, matched the Ecu. I could tell
they were on opposing sides ignition and fuel were ok.
So we hit at say 50% throttle to try to keep it running and rev'ed it up and down, they
came free one by one, you could hear them fire, and all of a sudden it was running on all
8 screaming away, it's often like this. I think the cure here was: just by having the
voltage slamming into the injectors coil and from the pressure of the fuel there or the
fact the fuel is removing the decomposed fuel deposits which cause injectors to stick,
could have been carbon on the spark plugs, or flooded cylinders from prior attempts at
starting (I doubt this, there is anti-flood protection).
These motors are sitting around in Japan or a wreaker’s yard, often for years. The first
start can often be a hard one to get there. Once there, they are MUCH easier to start
each time from there, till the point they get so easy to start its really a good idea for
manual conversion car to require the clutch to be depressed before it will start, for safety
reasons.
6.1 A Story
A mate once told me about a car that was so easy to start and so torque-y, that
someone working on the car touched the key one slot too far it started and rev'd up,
dropped off the axle stands, the employees hand on the pedal (cos thats where he fell)
and went backwards in reverse and slammed into a mustang that was in the shop
bounced a few times and wedged itself in between a mustang and something else folding
both doors around and forwards, nearly talking off the employees legs in the process.
The moral: if you can install a button that has to be pushed while the key is activated it
will improve safety, and make a handy anti-theft feature. I would put it on the NSW or
STA pin.
7 Watch for mechanical failures at start up

If it any stage while trying to start a motor you find you have no oil pressure, or hear
obvious knocking noises, stop. Fix the problem now before you wreak the engine.
Having an oil pressure gauge on an engine your about to fire up is not a must, but it’s a
damn good idea. Water temp does not matter unless you’re planning on running the
engine longer than 1-2mins (note a mechanic friend of mine regularly runs engines on a
stand for up to 10mins using water from a fast running hose in and out of it, he swears
its fine and I trust him, he’s a damn good mechanic.)
8 Pulsing, but patterned idle

A pulsing idle is (can) caused by the computer advancing the timing and ICSV (idle
control valve) not working for some reason. Idle control is not solely done the idle
control valve, it is also done by the computer advancing the timing to control the rpm,
the valve is opened based on how much o2 the o2 sensors pick up in the exhaust. So the
patterned nature of the up and down idle (pulsing idle, sometimes called a surge which it
is not) is caused by the computer advancing the timing and the valve not playing the
game when it's supposed too. If you ever have the pleasure of witnessing this it sounds
AWESOME, it’s like the engine has warmed over cams and is ‘hunting and seeking’ for
idle.
I recently completed a wire up on a customers car. From the first moment we started
the car it would seek for an idle in a patterned manner, it would pulse up and down,
sounded like a couple of hundred rpm (i.e. 750rpm - 1200rpm). It sounded like a v8
with injection and a mild cam. Actually, I really liked it. But, it's a mal-function and
customers have every right to have that addressed and solved. Here's how I solved it.
First, I scratched my head and wondered what the hell I did wrong. I checked the wiring
work, without checking for codes or even turning on the ecu. Everything was fine. In
fact, I hadn't touched this part of the wiring it was still factory. So I figured it wasn’t that
(correctly). The day ended and in the evening a friend who knows a hell of alot more
about 1uz's than me came over for dinner and afterward over a whiskey we chatted
about the idle control systems and how the 1uz actually does it. He reckoned it might be
several things, here were his thoughts:
• A bloody huge vacuum leak.

• The o2's error that was coming up for a left bank o2 (primary left)
• a malfunction in the ecu.
• a malfunction in the idle valve.
He reckoned the idle control valve is not needed. In fact you can just block it off and
forget about it, because all it does is give you a smoother idle, it will idle fine without it.
But, idle control is done by the o2's feeding the ecu information on the A/F ratio to give
the ecu a value that it use to set the fuel amount. The idle speed is set by the ecu
advancing and retarding the timing quickly to keep the rpm in a range of around 100rpm
either side of 600rpm (or so), so 1000rpm is a fast idle. He reckoned the idle valve
would prove to be stuck.
The customer in the back ground removed the valve and inspected it, didnt see anything
wrong and re-installed it. He then blocked off the idle values rubber tube and the pipe off
the intake (after the MAF / AFM ) to seal the leak. It no longer surged, but took a slightly
fast idle to the ear which sounded like 800 - 900rpm (no rev counter set up).
Right, this confirmed to me that it was the idle control valve. But I wanted to do
everything I could to clear the o2 code so I busted my balls testing everything and
ended up concluding that the plug for the o2 in question had all the right values at the
plug and if anything was wrong it was at the sensor itself. Tested the other plug for
reference and got the same value set. Confirmed the o2 errors were out of range values
for the sensor or the plug had a bad connection (it cleared later for no obvious reason).
Since my own project involves ITB's and custom upper manifold my factory manifolds
had been sitting under a workbench getting dusty for well longer than anyone would
really want to admit. Packed the upper into the car for several days in a row until it was
time to finish up and deal with it.
• I checked for a vacuum leak, very thoroughly - nothing.
• Removed the nuts and bolts holding the upper manifold being careful not to drop
the nuts into the valley (which I _always_ seem to do). Used a magnetic
telescope thing to take them out and put them back on. (I'm so careful not to
drop stuff into the valley because I just always seem to drop ~something~ down
there and anything metal down there could short out the starter cable = bad)
• Lifted the upper manifold up and then removed the idle valve and replaced with
the spare from under the bench.
• Problem fixed. perfect idle.
It was obvious right away that the valve was stuck in place. Sure the valve has perhaps
1.5mm - 2.5mm's worth of inward play which felt like it was on a spring. But the good
valve was WIDE open in its static position, the stuck valve was more closed than open,
and showed signed of corrosion (alloy oxide) in the passage, it also had alot of carbon
deposits, more than the other good one which was from and older motor. Suggests
motor spent quite a bit of time idling in Japanese traffic.
When i put my mouth to the good valve it was like huffing through an open cardboard
tube, easy as. The stuck on was more like three straws, it had resistance. It was clear
that neither valve could be easily opened to be for repair. I'm sure that you 'could' they
obviously make them 'somehow' but I didnt bother to try.
9 The Details
9.1 How to test the healthiness of an ecu
You can do this it's not without complications. It’s basically the same as wiring it up
though. The ecu's only real health indicator is the check engine light, or the diagnostic
plug. Other than that it falls down to the performance or lack of (in the sense that you
can see something isnt right) or a malfunction. There are more complex methods but
those are out of reach for DIY installers.
The diagnostic plug allows you to plug in a piece of equipment which will tell you all
about the ecu and how it sees the sensors which is relies on. That will tell you if it's ok.
It also involves a full set up, engine, loom, sensors, the works.
You 'could' hook the ecu up to power, hook the check engine light up, and see if it
pumps out codes for all the missing parts. (ref diagnostic how too).
To do this you will basically need to wire the ecu up to the loom, or a loom, or a
substitute for a loom, in part. You need to hook up earth, and power, and switched
power. That’s only a few wires though. Then you will need to refer to the wiring diagram
with great care, and make sure your connecting the right wires up. And, run the check
engine light. It's dirty, nasty, cheap, bit if the little light blinks in the way it should,
chances are it's fine.
It looks a bit like this.
User: 1uze30 on oldschool.co.nz
The other method is to send the ECU to a company like Anything Electronic Ltd
http://www.anythingelectronic.co.nz/ they will tell you if it's ok. It will cost money, but
they can also fix it.
If your health checking an ecu it must be for a reason, did you drop it ? Don’t panic, I've
done that quite a few times and they seem to be ok with it, well to a point. It is after all
a sensitive electronic device. We had one ecu on a work bench next to a bench grinder
for a couple of months. It fell, was put back up at least 3 times I know off, then my mate
moved it and it was left on a welding bench for about 6mths.
We expected it to be toast. It works. It’s in a hilux conversion right now running just
fine, which is amazing. It was installed because the engine came without a loom or ecu,
or a few other things, so it was patch up and got running so our friend could run through
cert and worry about the details later. He was told to replace it asap, he later used a
mega squirt (ms3).
9.2 - Looms and ECU's / Transmissions
9.2.1 Looms and ECU's

The engine will likely come from an importer, or been someone’s garage. Often the loom
is untouched, not uncommon to find something missing. Don’t be put off, but a MAF is a
problem they are now expensive ($150 - $250).
If engine has cut loom at the back of the cam cover don’t be put off, a cut loom is more
work to terminate at the ecu, because of missing wire. The problem with a cut loom is
ecu plugs. You need all of them, and the pins that go into them. You don’t really need a
long tail off each pin, some length is helpful.
Its not a big deal, the wiring time isn't doubled, but it is extra hours, as much as an
extra 10hrs, if you have the time and don’t mind the extra work it could be more
affordable.
Don’t worry about the 'right ecu' for the engine. Except for the VVTI engines, any 1uzfe
ecu can be grafted to work with any 1uzfe engine, the issue is more about having the
right plugs and the time taken to transfer it. It's the pin configurations, wiring diagrams,
and getting it all set up right, if is first wire up, don’t try match up / mis-matched
electrics, a big ask for a beginner, for aftermarket ecu installs some of the info here
could be useful.
9.2.2 Transmissions
There is a rumour that 1uzfe ecu's which operate the automatic as well will not rev
beyond 3000rpm once wired up, untrue. Possibly caused by reverse (speed) inhibitor in
some ecu's.
However, I had a long email conversation with one person who was certain his
installation was not rev’ing beyond 2800rpm because an inhibitor in the ecu. While at the
time of writing this he has yet to tell me he’s solved it, I ended up saying to him: your
car has no ecu faults, you’ve made no mistake, it will build rev’s to over 2800rpm, but
under load it falls flat. If your car was in my shop I would not even consider an ecu
related cause, I’d consider it a load related issue: so vacuum leak, or fuel pump fault,
etc. The key point here is if you can build rev’s over the inhibition point it’s something
else. It turns out the error he’d made was minor and detailed above in the FPR pin
information. It was just a simple wiring mistake, not even really a mistake.
I’ve yet to encounter this fabled failure to rev, others with real experience say its real. I
do believe them.
There is a rumour that a stand alone ecu is out there, it was installed into the Crown
Majesta (89? or is it 1990 ?), untrue I've seen it, it runs the automatic too. But if I'm
wrong and you find that ecu which was paired with a separate ECU to control the
transmission. grab it, grab both.
There is a rumour that "you cannot get a 1uzfe to work with a Surf Automatic", also
untrue. I've done it. It's three wires, there is more information about this further in the
document.
If you can physically mount the auto to a bell housing or adapter plate and have the
spline sit nicely in the torque converter it can be wired up to work properly. The problem
with the 1uz-fe automatics is that they are not a sliding yoke box. It is possible to
convert the 1UZFE range of gearboxes to be a sliding yoke box. I don’t think it’s worth
the effort. I would rather just install the 1UZFE and it’s stock gearbox and have a truck
type sliding spline drive shaft made up, easier and cheaper, a bit ugly in terms of it
being a heavy and expensive driveshaft, but effective and very strong.
9.3 - Working with the Loom Casings and Plugs.
9.3.1 Free the loom
Free the Loom as much as possible from the plastic mouldings/casings, ultimately you
want to separate the loom from the engine, there is a catch. Some of the plugs on the
1uz-fe engine in-so-far-as-I know might: are not used or any other engines. Well I’ve
hunted through one wreaker’s yard once searching for ISCV plug (Idle Solenoid Control
Value), and didn't find anything close so, take that as you will.
Here in New Zealand we get alot of Japanese importation from the Automotive
industries. We get some really great stuff imported. However by the time engines land
into New Zealand, they are usually well cooked. I have yet to see a 1uz engine without a
broken plug. The engines which feature in this section of the document was pretty
bad for plugs, this plug below is actually burned. I'm not sure what the story is, I guess
the engine it came from had a fire?
obviously, it got well baked.
9.4 Here is what most often happens

The injector plugs, because they are at the top of the motor take a pounding from
ambient heat, the little clip which holds the plug firmly onto the injector breaks away,
rendering the clip useless, the condition a plug which is broken could easily cause a
intermittent mis-fire. There are solutions you can buy brand new plugs for about $12.50
each, [edit]$15 each trademe.co.nz (seller:nzefi). Or the 4age (20v) plugs work just fine
and are pretty cheap at a wreakers they are generally not roasted either. The billet
injection rails (above) are nice, make big power just fine, if I was going to force the
induction on a 95 onwards motor I would ditch the cast fuel rails for the billet earlier
ones they are as good as anything in the aftermarket.
9.5 Brittle from heat, covered in corrosive dust

The plug above us is an ISCV plug, its missing a chunk, don’t do this, be careful with 1uz
plugs someone has tried to get the plug of its female counterpart with some sort of
metal tool and because the plug is brittle (they always are) it's relieved the stress by
coming to pieces instead of coming off, expect the plug to break up if you try that.
Despite the fact it’s missing a chunk and no longer seals from the environment in the
engine bay (which is a harsh) it is still usable, I cannot find a replacement for it.
Look at the state of this coil plug above and that’s not the worse one, the other plug was
hollow, again, 4age (20v) engines use these exact coils and plugs. Just visit a wreaker
and get another plug, chances are it will be just fine. If that fails, start looking to other
Toyota cars aged between 1990, and 2000.
There is no real reason why that coil plug could not be used for testing, but why would
you. It could induce a fault, causing you to doubt your work (perhaps all of your work, if
you’re new to wiring engines) and make you have the de-moralising task of going over
all your work in detail, stuff that, fix the problem and move forward from there, not
sideways.
9.6 Heat damage

If you find the engine your about to purchase has alot of broken plugs, reconsider the
purchase or negotiate a lower price, if all the plugs are very brittle it does not bode well
for the condition of the engine, it might be clean the exporter in Japan, or the importer
in New Zealand washes them well, but if plugs are baked so was the engine (over and
over), expect possibly of real mechanical problems if the plugs are falling apart in under
a firm squeeze.
9.7 Heat damage reasons ?

A another possible reason is Ultra Violet Light damage, or perhaps an engine that spent
alot on time in traffic, so it's done 100k in distance and 250k in hours!, sometimes
importers stack (already baked) engines up in a open yard, they sit in the sun for
months and bake, causing the plugs to become brittle and weak, brittle plugs are not a
good sign for the engine, means heat and sun will have effected other seals, cam cover
seal to a certain point it’s ok to think the engine might be mechanically fine though.
9.8 Before removing the lower plastic housing

Before you start removed the plastic mouldings/casings/housings and of course, the rest
of the loom, consider the above comments on heat damage. Forward (of the engine) end
of both plastic mouldings are plugs which may need to be unplugged. These will all be at
risk of breaking easily, so will injector plugs passengers side set of plugs are particularly
at risk. I'm very wearily of unplugging the four pin plug which carries the crank angle
signal, passengers side camshaft sensor, they always seem to crack this plug no matter
how hard I try not to. You do not 'have too' remove the entire loom like this, just .. look
all I’m saying is be careful, really careful.
9.9 When you've got the loom off
When you get the looms off it will probably dawn on you that it looks like a pretty
substantial piece of kit it’s around 80 odd wires, each single wire breaks down to a
simple connection like this, battery cable. Each wire is just a single connection it’s not
that hard to work out where they need to go.
I don’t normally feel the need to remove the entire loom. I tend to just free the loom up
to the forward plug on the passenger’s side and the water temp sensors. I know above I
talk about removing the entire loom. I also write about being very careful doing this
because of the age of the plugs and there propensity to break apart. Really try to avoid
going too far here.
9.10 Wiring up the MAF / Air Sensor

There are two types of 1uzfe mass air sensor, the older pre-95 cast alloy bodied type,
and the later model plastic bodied type. The wiring for each it totally different.
Pay attention to the different configurations of the two Air sensing devices on the 1UZ-FE
engine. It’s easy to look at the wrong diagram and be thinking you’ve made a mistake or
feel confused.
9.10.1 Karmen Vortex Air Flow Meter
The Mass Air Flow Sensors converts the amount of air drawn into the engine into a
voltage signal. The ECU needs to know intake air volume to calculate engine load. This is
necessary to determine how much fuel to inject, when to ignite the cylinder, and when to
shift the transmission (if there is an Automatic one present). The air flow sensor is
located directly in the intake air stream, between the air cleaner and throttle body where
it can measure incoming air. There are different types of Mass Air Flow sensors. The
vane air flow meter and Karmen vortex are two older styles of air flow sensors and they
can be identified by their shape. The newer, and more common is the Mass Air Flow
(MAF) sensor.
This air flow meter consists of the following components:

• Vortex Generator.
• Mirror (metal foil).
• Photo Coupler (LED and photo transistor).
Which result in a measurement of 'air flow volume'
9.10.2 Karman Vortex Air Flow Meter Operation

Intake air flow reacting against the vortex generator creates a swirling effect to the air
downstream, very similar to the wake created in the water after a boat passes. This
wake or flutter is referred to as a "Karman Vortex." The frequencies of the vortices vary
in proportion to the intake air velocity (engine load).
note: do not remove the honey comb, it effects the operation of the device. You wont wreak it, but it wont
measure as accurately so leave it alone.
The vortices are metered into a pressure directing hole from which they act upon the
metal foil mirror. The air flow against the mirror causes it to oscillate in proportion to the
vortex frequency. This causes the illumination from the photo coupler's LED to be
alternately applied to and diverted away from a photo transistor. As a result, the photo
transistor alternately grounds or opens the 5-volt KS signal to the ECU.
This creates a 5 volt square wave signal that increases frequency in proportion to the
increase in intake air flow. Because of the rapid, high frequency nature of this signal,
accurate signal inspection at various engine operating ranges requires using a high
quality digital multimeter (with frequency capabilities) or oscilloscope.
9.10.3 Later Model Plastic Type

There Air flow meters work by a different principal and are a much cheaper device to
make. The air flow cools a piece of metal which is suspended between two wires. There
is one difference between them and earlier type is the plug has a different configuration,
so pay attention to wiring, as the pins are different.
9.11 Wiring up the Camshaft sensors.
The camshaft sensors are one of three speed positioning sensors. There is a little tag
(protrusion) on the camshaft’s toothed cam belt wheel which the G and G1 sensors pick
up on. So, what does the ecu do with this information? Well by knowing the position of
number 1 cylinder and that’s in its compression stroke the ecu can use this information
for fuel injection timing, direct ignition systems and variable valve timing.
The factory ecu will not run at all without both G sensors being connected correctly.
There is a diagram below which shows the connection path to the ecu, I don’t normally
need to interact with the wiring for them or the crank speed sensor.
9.12 Wiring up the Crankshaft sensor.
In order to correctly time spark and injection events, the ECU monitors the relationship
between the Ne and G signals. With most engines, the ECU determines the crankshaft
has reached 10' BTDC of the compression stroke when it receives the first Ne signal
following a G1 (or G2). Initial timing adjustment is critical as all ECU timing calculations
assume this initial 10' BTDC as a reference point for the entire spark advance curve.
The Crankshaft sensor wiring travels down past passengers side plastic cover, stops at
the coil and then continues onward down to the lower pulley. In there is the sensor it’s
self and a small toothed wheel.
The engine speed sensor is the crank shaft sensor. It travels around in a shielded wire
which is basically two wires in a flexible woven wire casing then covered in a plastic
casing. The shielding is to protect the signals from interface and at the ECU end needs to
be earthed, you can basically collect all the shielded wire up and earth the lot in one go.
Each tooth generates a pulse, in AC wave format. There is no external power source
required. As the gear rotates faster there are more pulses produced. The ECU
determines speed based on the number of pulses received and then applies the correct
ignition and fuel maps in accordance with air volume (MAP/AFM) and air density
measurements (air temp). The number of pulses in one second is the signal frequency.
This is how the NE sensor looks in the factory set up (above and below images). As
above there is a toothed wheel, the sensor picks up on a cap and reports that to ecu.
The toothed wheel is in fact only an 8 tooth. Which is stuff all definition. In performance
engine setups there are 63:1 setups not 7:1. The increased definition allows for the
removal of the ‘G’ or camshaft sensors and complete reliance on the NE sensor as a high
definition source of crank positioning. Do not replace the factory toothed wheel unless
you are replacing the ecu completely for an aftermarket one.
9.12.1 Ignition Timing Strategy
The ECU determines ignition timing by comparing engine operating parameters with
spark advance values stored in its memory. The general formula for ignition timing
follows:
Initial timing + Basic advance angle + Corrective advance angle = Total spark advance.
Basic advance angle is computed using signals from crankshaft angle (G1), crankshaft
speed (Ne), and engine load (Vs or PIM) sensors. Corrective timing factors include
adjustments for coolant temperature (THW) and presence of detonation (KNK).
9.13 - Wiring up the O2 Sensors (four?)
In so far as I know there are two kinds of 1uz-fe o2 sensors. The heated four wire kind,
and the older two wire kind. Of course you find the older two wire kind on the older
engines, pre 1991 (yes there are older 1uz's). The four wire kind have a powered heater
in them to get them into a operational range and keep them there. The heating system
has to be hooked up for the o2's to work. You do want the o2's working. The are not
wide band sensors, just the on/off type. The wide band sensors tell you how much
oxygen is left in the exhaust gases, factory sensors do not, they just say to the ecu
something like ‘o2 found = add more gas next cycle’ and ‘no o2 = use less gas next
time’.
9.13.1 ... four o2's / some engine
If your motor has two o2’s on it and they are heated four wire ones. It’s quite possible it
might need two more. If it's a later model engine (1995 perhaps earlier; onwards) so
that’s the OBDII engines (note can still pull OBDI codes from checklight). Look some
1uz’s have four, and as far as I know do need the other two to get the engine to run in
open loop (ie normally). The only way to tell is to look at the loom and if you see two
separate bundles of o2’s wires then you will need another two sensors to install OR use
my work around which it detailed below.
The Ecu uses the difference between the two o2 sensors to determine if the catalyic
converter is still working, on each bank of the v8. So, the ECU expects the cat to be
there. There idea is for there to be a difference between the two o2 values, so you
cannot put them in right next to each other. If your going to use all four put one on or
near the header, and one well back after a muffler is ideal to clear the ecu of codes, per
side. If you install the o2's near each other you will clear the sub o2 code, but a new
code could show up about the condition of the CAT. If you going to do that you might as
well just wire the primary o2's to the sub o2 pins and clear the code that way, leaving
the non critical CAT code to come up and leave the engine like that. It's not like it's a big
deal that way.
These extra o2's are not normally included in with the engine, they are actually bundled
into the body/chassis harness because physically they are after the cat.
9.13.2 Two o2 sensors operating as four

You can clear the sub o2 code by connecting OXR2 directly to OXR1 and OXL2 directly to
OXL1. I do not connect the heating wires (e.g. (HTR2 to HTR1 and HTL2 to HTL1) there
was/is not any point in doing that since it wont clear the code at all. This cleared may
have cleared the primary o2 code for the left bank that I was getting in one install.
This gives the ecu two fake secondary o2 sensors (ghost ones), the problem is that there
is no difference between them and the primaries, there should be a difference between
the values that the primary and secondary o2's put out in a factory engine. However, it
clears the code, removes closed loop mode (limp) and hey, thats the goal.
Note: this was tested by two other installers on the 6th and 7th (Dec 2011), both reported that it clears the
code and closed loop (limp mode).
9.14 - Wiring up the Injectors
The injectors are actually really simple, they get a constant feed of positive power from a
switched power supply which I like to put on a relay which is switched by the ecu
(MREL), but there is no good reason it cannot be off the key.
9.14.1 1uzfe injectors.

The 1uzfe injectors are paired from 1989 to 1995, and sequential after that.
The paired injectors are set up like this,
Note the sharing of the cables for the ecu side. The splice is FAR up the loom, if you
planning on running sequential injection later move the splice down to very near the ecu
when your wiring the engine up.
At the Ecu end it looks like this: the pin has the usual plug location, and pin number, but
the designation is the special #number, so #30 in this case is injectors 6 & 8.
I'm thinking this is so simple: I'm not doing to bother to do one for the sequential
injection setups, on the post 95 or 97 engines, and the vvti engines, there is an image
below which shows the set up, I'm sure you understand, dont assume #10 = injector
one; it might well, but ya know = check it. It's just #10, #20, #30, #40, #50 etc. OR
it's #1, #2, either way it's # something (hash) and a number.
A few more words, the older engines have mostly solid primary colours for the injectors
(eg, red, blue, yellow, something else), but that doesn't mean some toyota worker
hasn't just grabbed the nearest full spool and used that, so be wary, never assume.
9.14.2 Random fuel and Injector information.
There are various ways to run injectors.

Group fire: where three or more injectors, say four, five, six, are fired at once.
Paired: where only two are fired at once, (heh: hence paired)
Sequential: where each injector is fired separately.
9.14.3 Injector Configurations
People put alot of stock into whether or not an engines injectors are fired in a certain
way. And there is some truth too it. The group firing is inefficient. Take the V6 in the
Hilux surfs, it's a group fire engine, it uses what we call two 'injector drivers', one to fire
one group, the other to fire the other group. This means to put fuel in 3# cylinder it has
to put fuel into two others as well. However manufactures take this into account and
reduce the amount of fuel being injected for what is pooling up in the air/fuel mix behind
the valve waiting for the next 'open event'.
That said: the best foot I can put forward for grouped injection still translates to high
fuel usage in the real world. The 3VZ-FE is still less efficient than the 1UZ-FE, I doubt it's
just the injection.
Consider the early Holden 304 engine, it has two injector drivers, it group fires 4
injectors to put fuel into one cylinder, I've always mocked them for wasting 75% of the
fuel they use by design, it's not a fair statement, but it is shockingly bad design. I mock
the ms1 and ms2 ecu's for the same reason.
In the 1uzfe set up there is a pulsation dampener between the fuel pump, and the fuel
rail. It looks like a regulator with no hose off it. If you put the fuel hoses on the wrong
way around, it will not start.
9.15 How to test the injectors
1uzfe injectors are prone to seizing. This is caused by fuel deposits breaking down while
the engine is idle and locking the 'gate' up. The method of dealing with this is to either
leave the injector sitting in petrol for a few hours or then tap with a few times while
running 12v across its two poles in an on/off manner. OR, leave them alone in place and
tap the offending injector while the motor is running with a screw driver in a 'sharp' but
NOT violent manner.
If you think the engine is not starting because of fuel spray aerostat or CRC cold crank
while cranking the engine down throttle body into the intake. Beware this can cause
burns to your arm hairs if you get a backfire. So take care now if the engine starts and
half runs then the spark side of it is ok. Keep the basics in your mind. Motors need: air,
fuel, spark and compression to run: bear that in mind and you'll be able to solve the
simple problems which come up and have complex causes.
It's an injected engine, but that doesn't mean that it won’t suffer from a simple problem.
It won’t run with no fuel, or spark, or a rag in the intake. Sure, it can suffer from very
complex problems too, but it's VERY important to keep the simple stuff in mind too.
9.16 The Fuel Regulator & Pulsation Dampener

Pulsation Dampener. (it evens out the fuel pulses from the pump, it does NOT impede
fuel delivery, or power output (to a point), once your making 300kw's+ you might as
well ditch this thing.
How you set your fuel system up is pretty much up to you. Bear in mind that two pumps
get pretty noisy in a hatchback. Not to bad in a coupe with a back seat and some sort of
barrier to the noise. Under the car is good place for them, but they are open to the
elements there. Be realistic, if it's a stock engine, all you need is a decent EFI pump and
you do not need a rising rate reg, and a surge tank, it all costs money, it's more things
to fail and go wrong, keep it simple: the stock system works well, try it for a while then
make changes.
Below we have an image from the megasquirt site which shows the basic fuel system.
This image shows how the EFI fuel system is set up. It's simplistic, but it is very
important to understand this.
This is the model for a surge tank set up, note the use of a low pressure fuel pump on
the surge tank.
If you use a high pressure 'lift pump' then the fuel will hit the surge tank, find it to be
full from the high volume lift pump, and back pressure will form behind the main pump,
this pressure will then flow back into the fuel tank via the surge tank's relief line.
Pumps (high volume ones like Bosch 44's) move alot of fuel, so heat will start to soak
into the fuel from the pressure and then into the tank. Once the tank starts heating up
the heat just keeps getting higher and higher. Expanded fuel is less dense. Hot fuel is
dangerous.
I made this mistake myself, the heat in the fuel lines and surge tank was clearly
obvious; the hot fuel tank scared the shit out of me, I shut the system down
immediately and disconnected the power. It was a big mistake to make, and it's not
something a fuel cooler will solve either.
There is where the injector resistor goes, if your replacing the 1uz-fe injectors with
bigger ones (assuming), that are low impedance; you have no need for resistors if you
set up is stock factory.
If your injectors are playing up, or the engine doesn’t seem to firing on all cylinders
there are solutions. It's very common for fuel deposits to cause the injector gate to lock
up. Sometimes all it takes it to keep rev'ing the motor. Other times you have to tap the
injectors while rev'ing the motor. If the injector(s) are really locked up you need to
remove them, take the rubber seat off the bottom, and soak them in fuel for a day, then
try tapping while switching them on/off (two person job).
If your really sure an injector is playing up, here's a tip from the Toyota manual for
someone with some serious electrical gear floating around.
9.17 Wiring up the ECU to turn on.
The Ecu turns on with very few wires. It’s all very well completing the wiring necessary
to turn it on, but that it no help if you cannot confirm it’s on. It does not make an ‘I’m on
noise’. The correct wires, and pins will vary ecu to ecu. Sorry, your back to the ‘get the
right diagram issue’. But I work it out something like this: first I guess. I look at the
plugs and try to figure it out and take a mental note of the wires I recognise. This is
likely not help you much. I’m looking for
• +12V wired to pin (BATT)

• (+B) and (+B1) both get 12volts when the Main EFI Relay is switched.
• (IGSW) gets a switched power 12volts from the ignition switch.
From there I connect the W to a light, and the other ‘pin’ on the light as switched power.
However you can also test if it’s on via the MREL output from the ecu (12+). To be
honest there isn’t much I can do to help you here beyond saying find the wires and
connect them. This is the final wiring set up on a 1992 ecu, note the fourth plug (far
right) which has only five wires connected and the rest De-pinned.
9.18 Wiring up the Alternator.

It might seem like a mystery but they are pretty simple devices. They get constant
power, switched power, and have an earth connection for the charge light, which goes
off when it’s charging, and is on just before you start the engine.
Here is where the cables are located. And this is a factory position for its mounting
• White (S)
o - Constant 12v feed (might be striped but it's always white as far as I
know)
• Yellow Black (IG)
o - (this might be another colour, I've seen it red, solid black, yellow black,
yellow (solid) blue (stripped) black, blue, use common sense) this is a
switched wire that turns the alternator on so thats live when the key is at
IGN (or stage two/ign on the key)
• Yellow (L)
o - (this one is always yellow as far as I know) when the alternator is on, it
will earth out so run a ohms test against the shell to find it if you get
confused) Dash Light, one side of the light goes to alt (earth side) and the
other side should be live/switched when the key is at IGN (or stage two on
the key)
This is another method of mounting the alternator if your not running other belts.
If you get stuck you can work out the wires using this method. Get to fuse holders, put 3
amp fuses in them. Work out the light wire if you can, by elimination applying work to
the other two through the fuses expecting to blow a few. You'll figure it out pretty fast
from there.
The Alternator has three wires. One has constant power. One as Switched power. One is
a earth connection for the alternator charge light so you connect that wire to a 12v light
(not an led unless you have a resistor on the power side otherwise it overloads it, and it
starts smoking and then flames out, I know .. I did that yesterday with a 12v led) and to
the other side of the light you put power. When the ignition is switched to IGN (stage
two), you get a charge / battery light come on. When the alternator is working the
charge light goes out, if not you screwed up wiring it up, so you've got the wrong wire
with a light on it, and the alternator might be working anyway or its not working and you
screwed up (if the light is still on when running).
If the alternator is running and working, you should see at least 13volts (13.25 – 13.8
perhaps) at the battery depending on the load from the stuff in the car that's running at
the time. It's a 120amp alternator put a decent cable off it. Fuse that cable with a total
of 120 - 140amp fuse(s) if you must/want too.
Then I'd disconnect the battery to reset the ECU, and make sure that the acc belt is
sufficiently tight. Measure the voltage on the battery with the engine off. Start the
vehicle and let the 1UZ ecu set the ICV with the extra alternator load (learning ecu:
needs to learn about the load of a alternator that's now offering resistance equal to 1-
2hp or more). Check the battery voltage to make sure it is 'actually' charging. If this is a
customers car repeat this check again before calling the job as 'done/finished/come get
your car now'.
When you locate the wires, mark them properly something like this.
Usually the Alternator plug is FUBAR. It's often brittle, very brittle. Usually broken in
someway, or easy to break. If you can leave it on and leave it alone ... do that. Extend
the wires as soon as you have a chance and bundle them up in a coil for later use
(marked using masking tape at the end of the wires which you will later be connecting.
Match the cable types, what I mean is dont put a tiny little gauge extension cable on
these wires, they carry real current, think 5-10amp capable wire not 1-2amp capable
wire and it wont fail on you later on down the track. I've felt these wires as warm after
1hr running in the shop once, you want to match the cable types here. Thats not always
the case, it is here.
9.19 - Water Temp, Tacho and Pin Order in Plugs

Find the water sensor’s in all these crazy lines. There are two water sensor, one for the
dash, one for the ecu which has two wires and it looks like this in the factory Toyota
diagram. This is a very important sensor which the ecu uses to set idle speed and
running warm fuel levels. It is however not a critical sensor.
10 Different Kinds of diagrams
For the sake of explaining how to wire up these engines I have picked on a particular
diagram and used that to explain how to wire up most things. This particular engine
diagram has comes from lextreme. I have also used exerts from Toyota diagrams. I wish
to point out the information here tells you what to do, and how to do it. It is not a
‘process’ document, it’s an explanation document. Below explains how you read the lex
diagrams, someone made these, they aren't Toyota diagrams.
10.1 Toyota Diagrams
Toyota diagrams look alot like this, most of the time. Sensors they are mostly just
variable resistors. Not many of the wires are much more than a negative or positive
connection, a fair few carry sensor signals which are just variable voltage very few of
those sensors are digital (i.e send a pulsed signal).This is a pretty old motor.
10.2 The difference:
The sensors might be visually different in the diagrams but that doesn’t seem to effect
one's ability to work with diagram. Although I find my eyes don’t like the lextreme ones
as much, harder to make out the details.
... in the 96ls diagram that looks like this;
In case you were interested, the TPS sends a signal which is voltage from 5+ downwards
(movement being increased resistance) it’s basically a freaking stereo volume knob, it's
just four wires, earth, then three others that go back to ECU pin's two are spliced in the
lex extreme diagram.
10.3 - Water Temp

Water Temp, as above there are two, one for the dash gauge and another for the ECU,
they are 400ohms each I tested one of them once, right after start it dropped to
396ohms, then just started failing down until it steadied out around midway. Pretty
device simple really.
... if you find an very old 1uz they may have a HUGE cold start injector located in the
hump on the centre upperside of the underside of the upper manifold.
11 Tacho and Igniters
11.1 Tacho
The ‘black but not always solid black’ wire is the tacho signal (*sigh-yeah-I-Know*)’ its
located on one igniter plug and usually runs off into the dash plug. It’s output signal, is
in a four (4) cylinder format so any digital four cylinder tacho will work off that. on that
plug with five wires and it is always solid black and noticeably thinner than the others.
Above are excerts from three diagrams, each shows the igniter who’s plug carrys the
tach signal. You can just swap the igniters around on the plugs, in effect there are two
tach signals one from each igniter. This is a good example of why the Lextreme
diagrams are kinda crap. See the lack of pin numbers in them. Very annoying to work
with, I much prefer original Toyota diagrams.
11.2 Igniters
This all seems pretty simple to wire up, it is. The plugs are interchangeable on the
igniters, so no1 igniter plug can go on number two and vice/versa. Key Point: you must
earth the case of both igniters’. Below is the factory 20v Silver top (cira 1991) igniter
and coil mounting which includes the starter relay.
On the factory engine, and on the 4age engine where this bracket earths the igniter, use
it (why not?): reshape it, it works well.
The advent of ECU spark management systems provides more precise control of ignition
spark timing. The centrifugal and vacuum advances are eliminated; in their place are the
engine sensors which monitor engine load (Vs or PIM) and speed (Ne). Additionally,
coolant temperature, detonation, and throttle position are monitored to provide better
spark accuracy as these conditions change.
The G sensor supplies the ECU with crankshaft position information which comes from
the camshafts (camshaft position sensors) is used as a reference for ignition and fuel
injector timing. Some engines use two G sensors, identified as G1 and G2.
In example, when the engine is cranked, an alternating current signal is generated by a

24-tooth Ne (crank sensor) pickup and a four-tooth G pickup (Camshaft Sensors). These
signals are sent to the ECU where they are conditioned and relayed to the
microprocessor.
The microprocessor drives a trigger circuit, referred to as IGt (TR1). The IGt signal is
sent to the igniter to switch the primary circuit power transistor on and off. While
cranking, IGt fixes spark timing at a predetermined value. When the engine is running,
timing is calculated based on signals from engine speed, load, temperature, throttle
position, and detonation sensors.
The IGt signal is advanced or retarded depending on the final calculated timing. ESA
calculated timing is considered the ideal ignition time for a given set of engine
conditions. If the ECU fails to see an Ne or G signal while it is cranking, it will not
produce an IGt signal, thus preventing igniter operation.
11.3 Igniter Operation

When the IGt signal goes high, the primary circuit power transistor TR2 turns on,
allowing cur-rent to flow in the coil primary winding. When the IGt signal goes low, the
igniter interrupts primary circuit current flow, causing voltage induction into the coil
secondary winding.
With the ESA system, the time at which the power transistor in the igniter turns on is
further influenced by a dwell control circuit inside the igniter. As engine rpm increases,
coil dwell time is increased by turning the transistor on sooner. Therefore, the time at
which the transistor is turned on determines dwell while the time the transistor is turned
off determines timing. Timing is controlled by the ECU; dwell is controlled by the igniter.
Controlling dwell within the igniter allows the same control over coil saturation time as
the ballast resistance does with the Conventional EFI ignition system. It allows maximum
coil saturation at high engine speeds while limiting coil and igniter current, reducing
heat, at lower speeds.
11.4 Spark Confirmation IGf

Once a spark event takes place, an ignition confirmation signal called IGf is generated by
the igniter and sent to the ECU. The IGf signal tells the ECU that a spark event has
actually occurred. In the event of an ignition fault, after approximately eight to eleven
IGt signals are sent to the igniter without receiving an IGf confirmation, the ECU will
enter a fail-safe mode, shutting down the injectors to prevent potential catalyst
overheating.
The IGt signal is relayed by the igniter to the proper power transistor circuit to trigger
the ignition event at the proper coil. The igniter also sends the standard IGf confirmation
signal to the ECU for each ignition event which takes place.
12 Wiring the Surf Automatic to run with the 1uzfe

G series Automatic (Hilux) gearboxs
In order to Get a Surf Automatic to work with a 1u engine you need to keep the Surf
Engine Ecu, so it can control the automatic gearbox which you've decided to keep for
some reason. In order for that to work this means you run two ecu's, because the Surf
Automatic (in a 1993) runs from the tandem'd up 1uz engine ecu. You will need to splice
some wires but only a few. Basically you trick the Surf ECU to think it's still got an
engine. Sure, it throws massive amounts of codes to the surf dash: when its all wired up
you put the 1uz check light up to the dash check light so as long as the surf ecu
functions its all ok.
.. on the surf ECU you need. (there is some confusion about these pins: you might be
able to do this with less pins: look around on the web for more information)
Splice VCC, VC, VTA, VS, IDL, from the 1uz engine to the same on the Surf ECU
Splice THC (water temp) from the 1uz ECU sensor engine to the THC on the Surf ECU
Splice THA (air temp) from the 1uz ECU sensor engine to the THC on the Surf ECU
Splice STA from the 1uz engine loom to the STA on the Surf ECU
Splice ... TPS from the 1uz engine to the TPS on the Surf ECU
13 - Diagnostic Codes OBD1
NOTE: Not all trouble codes will activate MIL (CHECK ENGINE light)
• Before proceeding, make sure the:
o CHECK ENGINE light circuit is functional. It should be ON when the ignition switch
is ON with the engine stopped.
o Battery voltage is above 11 volts.
o Throttle valve is fully closed (Throttle Position Sensor IDL points closed).
o Accessory switches (A/C, etc.) are OFF.
o Engine is at normal operating temperature (if possible).
• Turn ignition switch to ON position.
o Do not start the engine.
o Place a jumper wire across TE1 and El terminals in engine check connector.
(Or connect the TE1 pin via a wire to ground, best if thats the engine itself, even if it's
only through a wire.
• Count number of flashes from CHECK ENGINE light.
o If system is operating normally (with no detected faults), the CHECK ENGINE
light will blink continuously
and evenly about 2 times a second.
• Otherwise, the light will blink a number of times equal to the trouble code as
follows:
o The light blinks only (.5 second ON, .5 second OFF) when indicating a number.
o The light will be OFF for 1.5 seconds between the first digit and the second digit
of the code.
o If more than one code is stored, the light will be OFF for 2.5 seconds before the
next code is displayed.
o Once all code(s) have been displayed, the light will be OFF for 4.5 seconds and
then the whole sequence will repeat.
• The diagnostic code series will continue to repeat as long as the check connecter
terminals TEl and El are connected.
• When finished, remove the jumper wire (or wire connection to TE1)
• After repairing the malfunction, clear the codes from the ECUs memory.
Clearing Trouble Codes

All trouble codes must be purged from the ECUs memory after repairing the faults.
Otherwise, code(s) would remain in the ECUs memory indefinitely and would appear
along with a new code in the event of a future problem.
• Remove the EFI fuse (15A) for 30 seconds with the ignition switch OFF to clear
any codes. It may take longer than 30 seconds, depending on ambient temperature (the
lower the temperature, the longer the fuse must be left out).
• Trouble codes can also be cleared by disconnecting the vehicle battery. However,
other memory functions (clock, radio, etc.), will need to be reset.
• After the codes are cleared, road test the vehicle (as applicable for the fault) and
recheck if any codes reset. If so, it indicates that the trouble area has not been resolved.
Note: anything that starts with a single digit is pretty much serious bar a few of them.
OBD1 Codes
The serious codes.

1 Normal Condition
(this single blink, which is not something you would normally see on a converted engine)
2 Air Flow Meter signal. (will not stop it running, ECU will default to base map)
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal. (may rob power as engine will use base
map)
5 Oxygen Sensor. (may rob power as engine will use base map)
6 RPM signal (Crank Angle Pulse). (critical: engine should not run)
7 Throttle Position Sensor signal. (critical: engine should not run)
8 Intake Air Temperature Sensor signal. (will not stop it running, may rob power as
engine will use base map)
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal. (no effect to running, good to resolve)
12 RPM signal. (critical: engine should not run)
13 Knock Control CPU (ECM). (no effect to running, good to resolve)
13 RPM signal. (critical: engine should not run: 1uz-fe uses this signal to apply ignition
and fuel tables, without it, the ecu has no idea where to begin.)
14 Turbocharger Pressure. (ignore for 1uz-fe)
14 Ignition signal.
The not so serious codes

21 Left Oxygen Sensor. (resolve it, but it will run without it in base map.)
22 Engine Coolant Temperature Sensor signal. (will not stop it running, will rob power,
note: this is ECU temp sensor, not the dash one, there are two, this is the two wire one
more central at the front. )
25 Air-Fuel Ratio Lean. (resolve this)
26 Air-Fuel Ratio Rich. (resolve this)
27 Right Oxygen Sensor signal.
28 Left Secondary (Sub) Oxygen Sensor signal.
(good to resolve: it's thought this might engage base map, see four o2 section for how
to trick the ecu into thinking it has four when it only has two, and thus clearing this
code.)
29 Right Secondary (Sub) Oxygen Sensor signal.
(good to resolve: it's thought this might engage base map, see four o2 section for how
to trick the ecu into thinking it has four when it only has two, and thus clearing this
code.)
31 Air Flow Meter signal (Vacuum Sensor signal). (will not stop it running, may rob
power as engine will use base map)
32 Air Flow Meter signal. (will not stop it running, may rob power as engine will use base
map)
34 Turbocharger Pressure signal. (ignore for 1uz-fe)
35 Turbocharger Pressure Sensor signal. (ignore for 1uz-fe)
35 HAC Sensor signal.
41 Throttle Position Sensor signal. (critical: resolve)
42 Vehicle Speed Sensor signal. (no effect to running)
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
56 Hydrostatic Fan not connected.
59 Automatic Transmission Temp voltage (high out or of range) ?
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.
81 TCM Communication. (will show up when no automatic trans is in place on crown
majesta stand alone and other pre 95' ecus)
14 Connection Board for older cars / race cars

Below, pictures of a basic ECU board, made for a customer, to house the ECU and fuses,
relays required to run all the electrics in a race car, Uses high quality electrical parts that
cost about $500 on their own, could be created for less for a road car using off the shelf
parts from nation wide electrical supply chains. The ecu is meant to be on the below
side, with the top side in below photo. The relays outward as are the fuses. could be
done differently
The concept of putting the ecu and relays and fuses related to the engine (and not the
entire system as is the case here) stands useful. In high vibration environments soldier
will break. If your running 1500hp, in a drag car, or more, then boards like this are a NO
GO, you need to crimp and screw in each connection, same goes for trails trucks running
44's and being driving on the tar-sealed roads from time to time.
The parts come from Hella.co.nz,

The DT plugs are the most expensive part. At $36 each. The board is just Perspex, 3mm,
cut using a 1mmx110mm steel cutting disk, on grinder, with a steady hand and carefully
measured. The alloy angle is 2mm. The alloy angles make it easy to mount the thing
gives it strength too. There are holes every so often cable tie the loom.
The bolts used are too long to double up of nuts on the bottom side, with enough 'P
clamp loom' if needed. The 'P clamps' hold the board loom in place and make for a tidy
install. I had to re-make one or two ecu mounts or re-bend them to get ECU even.
I used heat shrink wrap, for sealing the joins and a 25-40watt solder iron?, 1mm solder
(tin kind). cable ties, different colours is helpful. The huge red cable is the power for the
board, plugs in well to cable blocks, from jay car $15, fuse ($12?) 100amp is enough.
The board has a 'common earth rail' for all relays, to allow the coil in them to trip when
power is applied to each one's switching side. There is also a separate Earth rail for
ECU's two earth connection (E1 and E2) to prevent interference; for good measure.
There is a tag, which holds the ecu’s loom as it comes in from the engine, there to take
strain off the plugs and wiring when in place.
Allow an inch between ECU and relays, cables get larger than expected once all in place.
The fuse box is from Hella about $136+gst, and you can get cheaper ones from
supercheap that are good, I doubt you need a 12x fuse box, may only need 8 row one
from s/cheap. ($21??). I had to remove the inner plate in the hella fusebox and solider a
wire to the pole on each side of each fuse, not sure why they only had two circuits in it.
However it only had two electrical channels in (I make also of use of relays) not enough
for the electrical system. I used a 80amp replay for the starter (factory spec), you don’t
need that, 40amps is fine, but the extra is good. You don’t really need so many relays,
chances are, you probably only need 6 relays.
1. Fuel pump,
2. Fuel injectors, (have constant power on IGN key position, earth is at the ecu for
injection trigger, duty cycle is an ecu function),
3. Ignition/spark (goes to the igniter's and coil),
4. Fan or not,
5. Engine main ACC (power all the little stuff),
6. Starter solenoid 80am/40amp.
Three Plug bundles,
• separate sensor outputs and basic power (style + quality + possible

interference),
• one for car side (inputs and outputs, e.g ignition and start), as well as ,
• another for tacho, oil, water, idiot light (oil low), etc etc). As well as .. check
engine/diag light,
• goes to engine loom, blends into the engine harness,
• the fourth bundle, which is not shown, is the actual loom which comes from the
engine.
15 - Swapping Between Series One and Series Two (non

VVTI) engine
The front plugs at right next to the Diagnostic plug are configured differently, they will
plug in fine. But the engine will not run, or even start.
• The coil wires need to be swapped over.

• So do the wires for the Crank Angle sensor.
• Note: never make a change to your wiring without confirmed the accuracy of my
information to your particular situation.
The information came about because someone (Nathan, on oldschool.co.nz) I know did
this swap. His car previously had a Series Two 1uz-fe (1997) and he swapped it out for a
(working) 1993 engine. The used the same ecu, (a 1997 one), which is fine, there's no
issue with that. But when it came time to start the engine, the error code 'RPM signal'
came up. Problem was (as I suggested at the time), the plug set near the diagnostic
plug is slight different between the version (it was just a guess at the time), with no RPM
signal the engine cannot determine its speed, so it can’t apply the ignition and fuel
tables.
16 Diagrams & Reference Material
- Technical Articles - Toyota Series - Resource Kit.
Technical Articles - Toyota Series
01 Electrical Fundamentals with questions
02 Electrical Circuits with questions
03 Electrical Components with questions
04 Analog vs Digital Meters with questions
05 Wire, Terminal and Connector Repair with questions
06 Automotive Batteries with questions
07 Toyota Starting Systems with questions
08 Toyota Charging Systems with questions
09 Understanding Toyota Wiring Diagram
10 Electrical Diagnostic Tools
11 Diagnosing Body Electrical Problems
12 Semiconductors with questions
13 Transistors with questions
14 Computers / Logic Gates with questions
15 Overview of Sensors & Actuators
16 Electronic Transmission #1 - Operation
17 Electronic Transmission #2 - Diagnosis with questions
18 Shift Interlock System
Technical Articles - Toyota Series - Engine Performance OBD
20 EFI#1 EFI System Overview

21 EFI#2 Air Induction System
22 EFI#3 Fuel Delivery & Injection Controls
23 EFI#4 Ignition System
24 Engine Controls #1 - Input Sensors
25 Engine Controls #2 - ECU/Outputs
26 Engine Controls #3 - Idle Speed Control 352KB
27 Engine Controls #4 - Diagnosis
Technical Articles Toyota - Series - Engine Performance OBD-II
31 Sensors#1 - Mode Sensors and Switches

32 Sensors#2 - Thermistors with questions
33 Sensors#3 - Position Sensors with questions
34 Sensors#4 - Air Flow Sensors with questions
35 Sensors#5 - Pressure Sensors with questions
36 Sensors#6 - Speed Sensors with questions
37 Sensors#6 - Oxygen / Air Fuel Sensors with questions
38 Sensors#8 - Knock Sensors with questions
39 Ignition#1 - Ignition Overview w/questions
40 Ignition#2 - Electronic Spark Advance w/quest
41 Ignition#3 - Distributor / Distributorless w/qu
42 Fuel System#1 - Overview with questions
43 Fuel System#2 - Injection Duration w/ques
44 Fuel System#3 - Closed Loop /Fuel Trim w/qu
46 OBDII#1 - Overview of On-Board Diagnostics
47 OBDII#2 - Serial Data
48 OBDII#3 - Data Interpretation
55 Emission#1 - Chemistry of Combustion
56 Emission#2 - Emission Analysis
57 Emission#3 - Engine Sub Systems
58 Emission#4 - Closed Loop Feedback Systems
59 Emission#5 - Electronic Spark Advance
60 Emission#6 - Idle Speed Control Systems
61 Emission#7 - Exhaust Gas Recirculation
62 Emission#8 - Evaporative Emission Control
63 Emission#9 - Positive Crankcase Ventilation
64 Emission#10 - Catalytic Converter
65 Emission#11 - Secondary Air
Technical Articles - Toyota Series - Automatic Transmissions
AT01 Fundamentals of Automatic Transmissions

AT02 Torque Converter
AT03 Simpson Planetary Gear Unit.pdf
AT04 Gear Selection and Function
AT05 Power Flow.pdf
AT06 Automatic Transmission Fluid
AT07 Transmission Oil Pump
AT08 valve Body Circuits
AT09 A340H Transfer.pdf
AT10 Electrical Control
AT11 Transmission Check, Adjustments and Diagnosis
AT12 Shift Lock System.pdf
AT13 Appendix
Technical Articles - Automatic Transmissions
AT21 Automatic Transmission Basics

AT22 U-Series Transaxle
AT23 Valve Body Circuits
AT24 Electronic Control System
AT25 Diagnostic Procedures
AT26 Diagnostic Tester
AT27 Remanufactured Transmission
AT28 Appendix.pdf
Technical Articles - Electrical (623 Training Course)
Elec01 Essential Electrical Concepts

Elec02 Electrical Circuits
Elec03 The Battery
Elec04 The starting System.pdf
Elec05 The Charging System
Elec06 Introduction to Electrical Signals.pdf
Elec07 Appendix.pdf
Elec11 Electrical Circuit Theory.pdf
Elec12 Using the Electrical Wiring Diagram
Elec13 Electrical Diagnostic Tools
Elec14 Six-Step Troubleshooting Plan
Elec15 Diagnosing Body Electrical Problems.pdf
Elec16 General Development of Multiplexing
Elec17 Appendix
Technical Articles - Toyota Series - Brakes
Brake01 Fundamental Principles

Brake02 Master Cylinder
Brake03 Drum Brakes
Brake04 Disc Brakes.pdf
Brake05 Brake Booster
Brake06 Parking Brake
Brake07 Brake Diagnosis
Brake08 Hydraulic Control
Brake09 Anti-Lock Brakes.pdf
Brake10 ABS Diagnosis.pdf
Brake11 Other ABS Actuators
Brake12 Traction Control System (TRAC)
Brake13 Appendix
Technical Articles - online instruction modules from this site
Control Devices
Circuit Protection
Understanding Relays with questions
Battery Basics v1.1
Battery Service v1.1
17 1UZ-FE NON-VVTI - Diagrams
17.1 - 1993 1uzfe Diagram

17.2 - 1992 Celsior 1uzfe UCF11 Diagram
17.3 - UZS131 Diagram
17.4 - 95'96 Lexus LS 400 Diagram (also works for 95,95 Crown
Majesta)
18 1UZ-FE VVTI - Diagrams
18.1 - VVTI Engine Wiring Diagram

18.2 - VVTI Engine Wiring Diagram - LF1ECS98
18.3 - VVTI Engine Wiring Diagram - LF1EA98
18.4 - VVTI Engine Wiring Diagram - 1998 Crown Majesta
19 2UZ-FE - Diagrams
- no diagrams available as yet
20 3UZ-FE - Diagrams
20.1 - 2000 - 2003 3UZ-FE Tundra Diagram
21 Links to Useful Sites
21.1 - Phil Bradshaw's Home Page

21.2 - Lextreme's Forum (Wiring Section)
21.3 - v-eight.com Forum (Wiring Section)

1uzfe Wiring

Uploaded by

Copyright:

Available Formats

1uzfe Wiring

Uploaded by

Document Information

Original Description:

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

1uzfe Wiring

Uploaded by

Copyright:

Available Formats

How to wire up a 1uz-fe

Note: this document is unfinished: most of the information is completed and a

Table of Contents .................................................................................................. 2

2.1.1 In the ecu loom: ............................................................................... 10

2.2 Anti-Flooding Feature .............................................................................. 11

2.4.1 The Method for counting the pins is: ................................................... 12

2.5 - Toyota wiring follows a certain kind of logic, ............................................ 16

2.5.1 Primary Sensors ............................................................................... 16

2.6 Missing the fourth plug ? a Dirty fix. .......................................................... 17

3 The Pin & Acronyms ....................................................................................... 18

3.1 The factory diagrams ............................................................................... 18

4 Pin Functions. ............................................................................................... 19

4.1.1 FPR Fuel Pump Relay, ........................................................................ 20

4.2.1 VC TPS – pin 4, ................................................................................ 23

4.4 34 Pin Plug ............................................................................................. 28

4.4.1 SLN + (Auto) Electric Solenoid #4 ...................................................... 29

5 The ECU is a learning ecu ............................................................................... 32

6.1 A Story .................................................................................................. 33

7 Watch for mechanical failures at start up .......................................................... 34

9.1 How to test the healthiness of an ecu ........................................................ 36

9.2.1 Looms and ECU's .............................................................................. 38

9.3 - Working with the Loom Casings and Plugs. .............................................. 39

9.4 Here is what most often happens .............................................................. 40

9.10.1 Karmen Vortex Air Flow Meter ............................................................ 43

9.11 Wiring up the Camshaft sensors................................................................ 45

9.12.1 Ignition Timing Strategy .................................................................... 48

9.13 - Wiring up the O2 Sensors (four?)............................................................ 48

9.13.1 ... four o2's / some engine ................................................................. 49

9.14 - Wiring up the Injectors .......................................................................... 50

9.14.1 1uzfe injectors. ................................................................................. 50

9.15 How to test the injectors .......................................................................... 55

10 Different Kinds of diagrams ......................................................................... 64

10.1 Toyota Diagrams..................................................................................... 65

11 Tacho and Igniters ..................................................................................... 67

11.1 Tacho .................................................................................................... 67

12 Wiring the Surf Automatic to run with the 1uzfe ............................................. 71

17.1 - 1993 1uzfe Diagram .............................................................................. 81

18 1UZ-FE VVTI - Diagrams ............................................................................. 81

18.1 - VVTI Engine Wiring Diagram .................................................................. 81

20.1 - 2000 - 2003 3UZ-FE Tundra Diagram ...................................................... 82

21 Links to Useful Sites ................................................................................... 82

21.1 - Phil Bradshaw's Home Page ................................................................... 82

2.1 - Quick and Dirty, this is what you connect + thoughts

2.1.1 In the ecu loom:

2.1.2 In the wiring loom:

2.1.3 Neutral Start Switch

2.1.4 Cold Start Injector

One installer commented;

2.2 Anti-Flooding Feature

I have nothing to add to that.

2.3 Just to get it running

2.4.1 The Method for counting the pins is:

2.4.2 Get it right: this is no time for mistakes

• An 80 fuse on the main line supplying the relays (constant power)

2.4.3 Do you need four relays ?

2.4.4 A few fuses too,

2.4.5 The dash plug in the ecu’s end of the bundle.

2.4.6 You will need to add in a plug

2.4.7 Important to get the Check Light Running ASAP