Engine Control (2UZ-FE)

From Power Source System (See Page 58)

7. 5A 20A
ACC EFI

8 1K 2

ACC L

L
AM1 IG1 F 3E W- G

ST1 W- G

F 3E L

7 AM2 IG2 6 B- R B- R

ST2 B- O
P
R

W- G
5 IC3 B B- W

B- O
L

L
I18
Ignition SW
P

2 2 2 2 2 2

3 2 1 5 5 1

C/OPN Relay
EFI Relay
ACC CUT
Relay

4 1 2 3 3 2
B

2 2 2 2 2 2

GR- B
W- G

B B

B- W
GR

E6
R

2
B

2 GR- B

2
1
30A AM2

W- B

10A
EFI C3 IC4 C15 IC4
NO. 2
1
2
GR- B
B

2 2
L- W
B

Connector

Connector

B A
Junction

Junction

A
J2

J4

B A
Battery GR- B
L- W

L- W

17 IC3 L- W
W- B

L- W

EB

74
2003 4RUNNER (EWD514U)
 FUEL PUMP

B
B- R
Relay

B- O

L- W
L- W
B- W
W- G
W- G

GR- B
1
2
G- R G- R G- R

2
2

D5 IC4

19 IM2
B- W

5
3
B- Y

2
2

1
2
B- R B- R

I1
F8
Fuel Pump

B- R
Resistor

J4
J40(A), J41(B) Junction

2
IB1
Junction F14 Connector

C
C
Connector Fuel Pump B- O B- O

5
4
W- B W- B W- B B- R

A A
A B
M

BO
B- O

A B
23 1E
J 8(A)
W- B W- B

B- R

10A
IGN
Junction

BL
Connector
B- O B- O B- R B- R

B A
B A
11 1J
I2

6 1D
J31(A), J32(B)
B- R

Junction
Connector
B- O B- O L L

B A
B B
9 E
3 E
C4 IC4

BATT

IGSW
1
EA1

G- R W- G W- G

2003 4RUNNER (EWD514U)

33 A
8 E
C17 IC4

FPR
MREL
B- R

GR- B W- G W- G W- G

10 E
15 A

FC
16 IC3

5 IM2

ACCR

Engine Control Module

J31(A), J32(B) P1
3
EB1

Junction Park/Neutral
Connector Position SW
J28
B B Junction

C A
A B
1 E
P

+B

Connector
E 4(A), E 5(B), E 6(C), E 7(D), E 8(E)
9

A
A

P P
B- R

16 A

B
NSW

A B
2 E
+B2
6

L- W
A

P
9 B
STAR

2
1
D
D

B R- G R- G R- G B- Y B- Y
27 A
17 A

1 IB2
C3 IE1
17 IM2
STA

CCV
D

V10
VSV (Canister Closed Valve)
B- Y

L- W
STA Relay
B- R

75
Engine Control (2UZ-FE)

B- R B- R B- R B- R B- R B- R B- R R- Y
E3 E3 E3 E3 E3 E3 E3
R- W

R- Y
B- R

B- R

B- R

B- R

B- R

B- R

B- R

B- R
Combination Meter

1 1 1 1 1 1 1 1 2 2

Ignition Coil and

Ignition Coil and

Injector No. 1

Injector No. 2

Injector No. 3

Injector No. 4

Injector No. 5

Injector No. 6

Injector No. 7

Injector No. 8

Igniter No. 1

Igniter No. 2
I10

I11

I12

I13

I14

I15

I16
I9

I1

I2
2 2 2 2 2 2 2 2 3 3
R- L

R- L

Connector

A
Junction

LG- B
J26

BR

LG
W

W
G

R
Y
L

A
R- L

1 A 2 A 3 A 4 A 5 A 3 B 6 C 5 C 9 A 8 A
#1 #2 #3 #4 #5 #6 #7 #8 IGT1 IGT2

E 4(A), E 5(B), E 6(C), E 7(D), E 8(E)

Engine Control Module

PTNK VC VTA1 VTA2 M+ M- GE01 THW VG E2G THA

21 E 18 A 21 A 31 A 3 C 2 C 17 C 19 A 30 A 29 A 20 A
L- R
O

Connector

B
Junction

L- R B W- R

B- W
R- B

Y- B
R- L
(* 1)

G
R
Y
J26

BR
B
L- R

7 IM2 22 IM2 5 6 4 2 1 2 5 4 2
VC VTA1 VTA2 M+ M-
Engine Coolant

VG E2G THA
Temp. Sensor

Mass Air Flow

L- R

BR
O

Meter
M1

E2 E2 +B
E2

A10 IE1 A16 IE1 A17 IE1 1

T2 3 1 3
Throttle Control Motor
L- R

BR

Throttle Position Sensor

O

L- W
BR

BR

BR

10 BC2 8 BC2 16 BC2 BR BR BR BR

I8 I8 I8
L- R

BR
O

2 3 1
PTNK VCC GND

V8
Vapor Pressure Sensor
L- W

18
L- W L- W
IM2

76
2003 4RUNNER (EWD514U)
 I3

BR
R- Y

L- W
L- W
R- W
V2 Ignition Coil and
VSV (EVAP) Igniter No. 3

2
1
L- W Y- R

34 A
3
2
L- W R- W

PRG
25 A
E3

IGT3
BR BR

28 A

I8
E2
I4

R- W
Ignition Coil and
(* 1) Igniter No. 4

L- W
3
2
L- Y R- Y

11 A

BR
E3

E
E
E
IGT4

E
2
3
L- W L- W G

J28
22 B

+B
OX
OX2A

Junction
E
E
E

Connector
I5
R- W

Ignition Coil and

4
1
BR B- L Igniter No. 5

33 B

I8
E1
HT

L- W
L- W
L- W
HT2A
3
2
B- L R- W

12 A
E3
R- Y

IGT5
H7
Heated Oxygen Sensor

BR
(Bank 2 Sensor 1)

I6
(* 1)
R- W

Ignition Coil and

I9
Igniter No. 6
3
2

G R- Y

BR
26 A
E3

2
3
L- W R

IGT6

23 B

+B
OX
OX1A
Engine Control Module

BR
I7

4
1
BR LG
R- Y

Ignition Coil and

4 B

I8
E1
HT
Igniter No. 7

HT1A
E 4(A), E 5(B), E 6(C), E 7(D), E 8(E)
3
2

G- W R- Y

2003 4RUNNER (EWD514U)

H5
13 A
E3

Heated Oxygen Sensor IGT7

BR
(Bank 1 Sensor 1)

(* 1)
I8
R- Y

R- W

Ignition Coil and

Igniter No. 8

2
3
3
2

L- W W 21 B G- B R- W
10 A

+B
OX
E3

IGT8

OX2B

BR
4
1
BR P
25 B

I8
E1
HT
R- W
HT2B
23 A
IGF2

H8
Heated Oxygen Sensor
* 1 : Shielded

(Bank 2 Sensor 2) R- Y
24 A
IGF1

R- Y B- Y
23 C
2 D

A/C Lock Sensor MG CLT Relay

LCKI
ACMG

BR
BR

(* 1)

L- W

77
Engine Control (2UZ-FE)

From Power Source System (See Page 58)

1 1

7. 5A 10A 10A
STA ETCS STOP
NO. 2

2 2
A24
Accel Position Sensor 2 1K 2 2
G- Y

G- W
B 3C
2

Stop Light SW
L- Y

GR
VPA1 VPA2 VCP1 VCP2 EP1 EP2
6 3 4 1 5 2 B 3C

S12
H A

J31(A), J32(B)
LG- B
W- R

V- W
W- L
R- B

G- Y
B- Y

Connector
Junction
G- Y
6 IM2 C5 IC4
15 IC3 E B

Connector
C16 IC4 C13 IC4 A8 IC4 9 IC3 C11 IC4 8 IC3 E

Junction
J4
LG- B
W- R

V- W
W- L
R- B

G- Y
B- Y

L- Y

GR
E
G- Y

22 E 23 E 26 E 27 E 28 E 29 E 12 C 6 D 19 D
VPA VPA2 VCPA VCP2 EPA EPA2 STSW +BM STP

E 4(A), E 5(B), E 6(C), E 7(D), E 8(E)

Engine Control Module

OX1B HT1B NE+ NE- G2+ G2- KNK2 KNK1

29 B 5 B 25 C 24 C 27 C 32 C 2 B 1 B
G- Y
(* 1)

(* 1)

(* 1)

(* 1)

(* 1)
W

W
B

B
L

I9

E3
Heated Oxygen Sensor

(* 1)
I9
BR

3 1
(Bank 1 Sensor 2)

1 1
Position Sensor

Position Sensor

OX HT
Crankshaft

Camshaft

1 EB1 2 EB1 4 EB1

BR

+B E1
H6

C4

C1

BR

BR
(* 1)

(* 1)

2 4 2 2
W

B
L- W

BR

E4
1 1
BR
Knock Sensor 2

Knock Sensor 1

C
(* 1) BR C C BR
I9
BR BR C J28
K2

K1

Junction
Connector
C
BR

L- W

EF

78
2003 4RUNNER (EWD514U)
 * 1 : Shielded

GR- R

T8 F9 A32
Transponder Key 4WD Control S 8(B), S 9(C) Airbag Sensor
Computer ECU Skid Control ECU 16 B Assembly
SP1
R- Y

EFIO EFII L4 NEO ENG+ ENG- TRC+ TRC- GSW2 P- L

6 7 24 7 C 14 C 22 C 24 C 16 C 23
(4WD)
W- L

R- Y

P- L
R- W

J35(A), J36(B)

J29(A), J30(B)
F A E A
Connector

Connector

Connector
W- R

H B
L- R

Junction

Junction

Junction
J30(B)

W
R
P

Y
2 IL1
H B H B A B
(4WD)
W- L

R- W
R- Y

P- L
27 D 26 D 4 D 17 E 24 E 30 E 25 E 31 E 14 E 18 E 20 E 19 E
IMI IMO L4 NEO ENG+ ENG- TRC+ TRC- F/PS SIL TC WFSE

E 4(A), E 5(B), E 6(C), E 7(D), E 8(E)

Engine Control Module

THWO ACLD THE A/CS E01 E02 E03 ME01 E1 4WD HP EOM SPD TACH W ELS
14 D 33 D 32 D 31 D 7 A 6 A 7 C 4 C 1 C 8 B 1 D 15 E 17 D 5 E 11 E 12 E
L- B

H B
J31(A), J32(B)

GR- G

(4WD)
BR- B
Connector

W- B

W- B

W- B

W- B

W- B

W- B

B- W
B- R

V- R

R- B

L- R
BR

BR
Junction

E A
L- B

4 IK1 2 IK1 3 IK1 4 II1

C 3D C B C B
J33(A), J34(B)

C C
L- R
Connector
Junction

C 3D J26 15
C
GR- G

BR- B
B- R

Junction B A ELS1
Connector
L- B

7 A 18 A 7 B 17 B B4
TWI ACLD THE ACS Body ECU
W- B
BR

R- B
A16(A), A17(B)
A/C Control Assembly B- W

V- R
W- B

W- B

W- B

W- B

A
J37
Junction
Connector

EE EF IK

79
2003 4RUNNER (EWD514U)
Engine Control (2UZ-FE)

From Power Source System (See Page 58)

1 1

7. 5A 7. 5A 10A
OBD GAUGE DOME
GR- R

R
2 2

2 4 1G 2

J 8(A), J 9(B)

Connector
R- Y H A D

R- L

Junction

R
Connector
Junction
P- L

J7
O
D
F B C2 IC4
C 3C A 3A

R
R
R- W C14 IC4
15 C 16 C
C 3C A 3A
R- Y
P- L

Speedometer
Connector

H G

Tachometer
Junction

Indicator Lamp
J18

Malfunction

H G
R- W

O
R- Y
P- L

C 8(A), C 9(B), C10(C)

15 13 7 16
Combination Meter

WFSE TC SIL BATT

SG CG
5 D1 4 7 A 4 B 6 B 5 B 13 C
Data Link Connector 3
GR- R

B- W

V- R
R- B

BR
J 8(A), J 9(B)

C B 1 1G
Connector
Junction
W- B
BR

C A 11 1K
V- R

7 IM1

E B 3D
J22
B- W

9 IM2 Junction
Connector
E
B 3D
V- R
J31(A), J32(B)

J29(A), J30(B)

G A B A
BR

Connector

Connector
W- B

Junction

Junction

F B D B
B- W

V- R

BR

R- B

B- W

V- R
W- B
BR

A
J5
Junction
Connector

EF IG EF

80
2003 4RUNNER (EWD514U)
 System Outline
The engine control system utilizes a microcomputer and maintains overall control of the engine, transmission etc. An outline
of the engine control is given here.
1. Input Signals
(1) Engine coolant temp. signal circuit
The engine coolant temp. sensor detects the engine coolant temp. and has a built-in thermistor with a resistance which
varies according to the engine coolant temp. The engine coolant temp. is input into TERMINAL THW of the engine
control module as a control signal.
(2) Intake air temp. signal circuit
The intake air temp. sensor is installed in the mass air flow meter and detects the intake air temp., which is input as a
control signal to TERMINAL THA of the engine control module.
(3) Oxygen sensor signal circuit
The oxygen density in the exhaust emission is detected and is input as a control signal from the heated oxygen sensors
to TERMINALS OX1A, OX1B, OX2A and OX2B of the engine control module.
(4) RPM signal circuit
The camshaft position is detected by the camshaft position sensor and is input into TERMINAL G2+ of the engine
control module as a control signal. Also, the engine RPM is detected by the crankshaft position sensor and the signal is
input into TERMINAL NE+ of the engine control module.
(5) Throttle position sensor signal circuit
The throttle position sensor detects the throttle valve opening angle as a control signal, which is input into TERMINALS
VTA1 and VTA2 of the engine control module.
(6) Vehicle speed circuit
The vehicle speed sensor detects the vehicle speed, and the signal is input into TERMINAL SPD of the engine control
module via the combination meter, from TERMINAL SP1 of the skid control ECU.
(7) Battery signal circuit
Voltage is constantly applied to TERMINAL BATT of the engine control module. When the ignition SW is turned on, the
voltage for engine control module start up power supply is applied through the EFI relay, to TERMINALS +B and +B2 of
the engine control module. The current from the IGN fuse flows to TERMINAL IGSW of the engine control module, and
voltage is constantly applied to TERMINAL +BM.
(8) Intake air volume signal circuit
The intake air volume is detected by the mass air flow meter, and is input as a control signal to TERMINAL VG of the
engine control module.
(9) Stop light SW signal circuit
The stop light SW is used to detect whether the vehicle is braking or not, and the signal is input into TERMINAL STP of
the engine control module as a control signal.
(10) Starter signal circuit
To confirm whether the engine is cranking, the voltage applied to the starter motor when the engine is cranking is
detected, and is input into TERMINAL STA of the engine control module as a control signal.
(11) Engine knock signal circuit
Engine knocking is detected by the knock sensors, and is input into TERMINALS KNK1 and KNK2 of the engine control
module as a control signal.
(12) A/C SW signal system
The operating voltage of the A/C magnetic clutch is detected and input in the form of a control signal to TERMINAL A/CS
of the engine control module.

81
2003 4RUNNER (EWD514U)
Engine Control (2UZ-FE)

2. Control System
∗ SFI system
The SFI system monitors the engine condition through the signals input from each sensors to the engine control module.
The control signal is sent to the engine control module TERMINALS #1, #2, #3, #4, #5, #6, #7 and #8 to operate the
injector (Fuel injection). The SFI system controls the fuel injection by the engine control module in response to the driving
conditions.
∗ ESA system
The ESA system monitors the engine condition through the signals input from each sensors to the engine control module.
The best ignition timing is decided according to this data and the data memorized in the engine control module. The
control signal is output to TERMINALS IGT1, IGT2, IGT3, IGT4, IGT5, IGT6, IGT7 and IGT8, and these signals control the
igniter to provide the best ignition timing.
∗ Heated oxygen sensor heater control system
The heated oxygen sensor heater control system turns the heater on when the intake air volume is low (Temp. of exhaust
emission is low), and warms up the heated oxygen sensors to improve their detection performance. The engine control
module evaluates the signals from each sensors, and outputs current to TERMINALS HT1A, HT1B, HT2A or HT2B to
control the heater.
∗ Fuel pump control system
The engine control module supplies current to TERMINAL FPR, and controls the operation speed of the fuel pump with
the FUEL PUMP relay.
∗ ACIS
The ACIS includes a valve in the bulkhead separating the surge tank into two parts. This valve is opened and closed in
accordance with the driving conditions to control the intake manifold length in two stages, for increased engine output in all
ranges from low to high speeds.
∗ ETCS-i
The ETCS-i controls the engine output at its optimal level in accordance with the opening of the accelerator pedal, under
all driving conditions.
∗ Engine start control system
The engine control module allows power to be supplied from the TERMINAL STAR to the STA relay via park/neutral
position SW until complete combustion is confirmed by engine RPM after the detection of ignition SW ST signal by the
TERMINAL STSW.
With this arrangement, engine can be started without holding the ignition key in the ST position. At the same time, the
TERMINAL ACCR is controlled so that the engine control module turns off ACC CUT relay, shutting off power to the
accessories.
3. Diagnosis System
When there is a malfunction in the engine control module signal system, the malfunctioning system is recorded in the
memory. The malfunctioning system can be found by reading the code displayed on the malfunction indicator lamp.
4. Fail-Safe System
When a malfunction has occurred in any system, there is a possibility of causing engine trouble due to continued control
based on that system. In that case, the fail-safe system either controls the system using the data (Standard values)
recorded in the engine control module memory, or else stops the engine.

82
2003 4RUNNER (EWD514U)
 Service Hints
EFI Relay
5-3 : Closed with the ignition SW at ON position
E2 Engine Coolant Temp. Sensor
1-2 : Approx. 15.0 kΩ (-20°C, -4°F)
: Approx. 2.45 kΩ (20°C, 68°F)
: Approx. 0.32 kΩ (80°C, 176°F)
: Approx. 0.14 kΩ (110°C, 230°F)
E4 (A), E5 (B), E6 (C), E7 (D), E8 (E) Engine Control Module
BATT-E1 : Always 9.0-14.0 volts
+BM-E1 : Always 9.0-14.0 volts
IGSW-E1 : 9.0-14.0 volts with the ignition SW at ON position
+B, +B2-E1 : 9.0-14.0 volts with the ignition SW at ON position
VC-E1 : 4.5-5.5 volts with the ignition SW at ON position
VTA2-E1 : 2.0-2.9 volts with the ignition SW on and throttle valve fully closed
: 4.7-5.1 volts with the ignition SW on and throttle valve fully open
VTA1-E1 : 0.4-1.0 volts with the ignition SW on and throttle valve fully closed
: 3.2-4.8 volts with the ignition SW on and throttle valve fully open
VPA-E1 : 0.3-0.9 volts with the ignition SW on and throttle valve fully closed
: 3.2-4.8 volts with the ignition SW on and throttle valve fully open
VPA2-E1 : 1.8-2.7 volts with the ignition SW on and throttle valve fully closed
: 4.7-5.1 volts with the ignition SW on and throttle valve fully open
THA-E1 : 0.5-3.4 volts with the idling, intake air temp. 0°C (32°F) -80°C (176°F)
THW-E1 : 0.2-1.0 volts with the idling, engine coolant temp. 60°C (140°F) -120°C (248°F)
STA-E1 : 6.0 volts or more with the engine cranking
W-E1 : 9.0-14.0 volts with the idling and malfunction indicator lamp off
SPD-E1 : Pulse generation with the vehicle moving
STP-E1 : 7.5-14.0 volts with the brake pedal depressed

: Parts Location
Code See Page Code See Page Code See Page
A16 A 36 I2 33 (2UZ-FE) J28 38
A17 B 36 I3 33 (2UZ-FE) J29 A 38
A24 36 I4 33 (2UZ-FE) J30 B 38
A32 36 I5 33 (2UZ-FE) J31 A 38
B4 36 I6 33 (2UZ-FE) J32 B 38
C1 32 (2UZ-FE) I7 33 (2UZ-FE) J33 A 38
C4 32 (2UZ-FE) I8 33 (2UZ-FE) J34 B 38
C8 A 37 I9 33 (2UZ-FE) J35 A 38
C9 B 37 I10 33 (2UZ-FE) J36 B 38
C10 C 37 I11 33 (2UZ-FE) J37 38
D1 37 I12 33 (2UZ-FE) J40 A 40
E2 32 (2UZ-FE) I13 33 (2UZ-FE) J41 B 40
E4 A 37 I14 33 (2UZ-FE) K1 33 (2UZ-FE)
E5 B 37 I15 33 (2UZ-FE) K2 33 (2UZ-FE)
E6 C 37 I16 33 (2UZ-FE) M1 33 (2UZ-FE)
E7 D 37 I18 37 P1 33 (2UZ-FE)
E8 E 37 J2 33 (2UZ-FE) S8 B 39
F8 32 (2UZ-FE) J4 38 S9 C 39
F9 37 J5 38 S12 39
F14 40 J7 38 T2 33 (2UZ-FE)
H5 32 (2UZ-FE) J8 A 38 T8 39
H6 32 (2UZ-FE) J9 B 38 V2 33 (2UZ-FE)
H7 32 (2UZ-FE) J18 38 V8 41
H8 32 (2UZ-FE) J22 38 V10 41
I1 33 (2UZ-FE) J26 38

83
2003 4RUNNER (EWD514U)
Engine Control (2UZ-FE)
: Relay Blocks

Code See Page Relay Blocks (Relay Block Location)

2 22 Engine Room R/B (Engine Compartment Left)

: Junction Block and Wire Harness Connector

Code See Page Junction Block and Wire Harness (Connector Location)
1D
24 Engine Room Main Wire and Driver Side J/B (Lower Finish Panel)
1E
1G
1J 25 Instrument Panel Wire and Driver Side J/B (Lower
( Finish Panel))
1K
3A
3C
28 Instrument Panel Wire and Center J/B (Instrument Panel Brace RH)
3D
3E

: Connector Joining Wire Harness and Wire Harness

Code See Page Joining Wire Harness and Wire Harness (Connector Location)
EA1 44 (2UZ-FE) Engine No.2 Wire and Engine Room Main Wire (Under the Engine Room R/B)
EB1 44 (2UZ-FE) Engine No.2 Wire and Engine Wire (Near the Starter)
IB1
48 Floor No
No.2
2 Wire and Engine Room Main Wire (Left Kick Panel)
IB2
IC3
48 Instrument Panel Wire and Engine Room Main Wire (Left Kick Panel)
IC4
IE1 50 Instrument Panel Wire and Floor No.2 Wire (Left Kick Panel)
II1 50 Instrument Panel Wire and Instrument Panel Wire (Instrument Panel Brace LH)
IK1 50 Instrument Panel Wire and Instrument Panel Wire (Left Upper Side of the Glove Box)
IL1 50 Instrument Panel Wire and Instrument Panel Wire (Right Upper Side of the Glove Box)
IM1
52 Engine Wire and Instrument Panel Wire (Right Side of Blower Unit)
IM2
BC2 54 Frame Wire and Floor No.2 Wire (Under the Rear LH Seat)

: Ground Points

Code See Page Ground Points Location

EB 44 (2UZ-FE) Front Left Fender
EE 44 (2UZ-FE) Rear Side of Right Bank Cylinder Block
EF 44 (2UZ-FE) Rear Side of Left Bank Cylinder Block
IG 48 Left Kick Panel
IK 48 Right Kick Panel
BL 54 Floor Seat Crossmember LH
BO 54 Rear Pillar LH

: Splice Points

Code See Page Wire Harness with Splice Points Code See Page Wire Harness with Splice Points
E3 44 (2UZ-FE) Engine Wire I2 50 Engine Room Main Wire
E4 44 (2UZ-FE) Engine No.2 Wire I8
50 Engine Wire
E6 44 (2UZ-FE) I9
Engine Room Main Wire
I1 50

84
2003 4RUNNER (EWD514U)
 Memo

85
2003 4RUNNER (EWD514U)