Troubleshooting A442

AT−14
AUTOMATIC TRANSMISSION − TROUBLESHOOTING
TROUBLESHOOTING
Trouble occurring in the electronically controlled transmission can stem from one of three
sources: the engine, the electronically controlled transmission electronic control unit or the
transmission itself. Before troubleshooting, determine in which these three sources the problem
lies, and begin troubleshooting with the simplest operation, gradually working up in order of
difficulty.
BASIC TROUBLESHOOTING
Before troubleshooting an electronically controlled transmission, first determine whether the
problem is electrical or mechanical. To do this, just refer to the basic troubleshooting flow−chart
provided below.
If the cause is already known, using the basic troubleshooting chart below a long with the general
troubleshooting chart on the following pages should speed the procedure.
Read Diagnostic Trouble Code Bad

(See page AT−18)
Repair or Replace
Preliminary Check Bad

(See page AT−25)
Manual Shifting Test

(See page AT−28)
Bad
Stall Test, Time Lag Test and

Electrical Control System Check Hydraulic Test and Road Test
Bad
Repair or Replace Repair Transmission

AT−15
NOTICE: Refer to ’94 A442F Automatic Transmission Repair Manual when * mark appears in the
column for page numbers.
Problem Possible cause Remedy Page

Fluid discolored or Fluid contaminated Replace fluid AT−25
smells burnt Torque converter clutch faulty Replace torque converter clutch AT−70
Transmission faulty Disassemble and inspect *
transmission
Vehicle does not Manual linkage out of adjustment Adjust linkage AT−26
move in any forward Valve body or primary regulator faulty Inspect valve body *
position or reverse Parking lock pawl faulty Inspect parking lock pawl *
Torque converter clutch faulty Replace torque converter clutch AT−70
Converter drive plate broken Replace drive plate AT−71
Clean screen *
Oil pump intake screen blocked
Disassemble and inspect *
Transmission faulty transmission
Shift lever position Manual linkage out of adjustment Adjust linkage AT−26
incorrect Manual valve and lever faulty Inspect valve body *
transmission
Harsh engagement Throttle cable out of adjustment Adjust throttle cable AT−26
into any drive position Valve body or primary regulator faulty Inspect valve body *
Accumulator pistons faulty Inspect accumulator pistons *
transmission *
Delayed 1−2, 2−3 or Electronic control faulty Inspect electronic control AT−29
3−0/13 up−shift, or Valve body faulty Inspect valve body *
down−shift from Solenoid valve faulty Inspect solenoid valve AT−38, 39
OlD−3 or 3−2 and
shifts back to O/D
or 3
Slips on 1−2, 2−3 or Manual linkage out of adjustment Adjust linkage AT−26
3−0/1) up−shift, or Throttle cable out of adjustment Adjust throttle cable AT−26
slips or shudders on Valve body faulty inspect valve body *
acceleration Solenoid valve faulty Inspect solenoid valve AT−38, 39
transmission
Drag, binding or Manual linkage out of adjustment Adjust linkage AT−26

tie−up on 1−2, 2−3 or Valve body faulty Inspect valve body *
3−OlD up−shift Transmission faulty Disassemble and inspect *
transmission
AT−16
NOTICE: Refer to ‘94 A442F Automatic Transmission Repair Manual when * mark appears in the
column for page numbers.
Problem Possible cause Remedy Page

No lock−up in 3rd Electronic control faulty AT−29
Inspect electronic control *
or O/D Valve body faulty inspect valve body
Solenoid valve faulty AT−38, 39
Inspect solenoid valve
Transmission faulty Disassemble and inspect
transmission
AT−26
Harsh dawn−shift Throttle cable out of adjustment Adjust throttle cable
AT−26
Throttle cable and cam faulty Inspect throttle cable and cam
Accumulator pistons faulty Inspect accumulator pistons
Valve body faulty Inspect valve body
transmission
AT−38, 39
No down−shift when Valve body faulty Inspect valve body AT−29
coasting Solenoid valve faulty Inspect solenoid valve
Electronic control faulty Inspect electronic control
AT−26
Down−shift occurs Throttle cable faulty Inspect throttle cable AT−38, 39
too quickly or too Valve body faulty Inspect valve body AT−29
late while coasting Transmission faulty Disassemble and inspect
Solenoid valve faulty transmission
Electronic control faulty Inspect solenoid valve
Inspect− electronic control
Solenoid valve faulty Inspect solenoid valve AT−38, 39

No 0/0−3, 3−2 or 2−1 AT−29
kick−down
Valve body faulty Inspect valve body
Solenoid valve faulty Inspect solenoid valve AT−38, 39

No engine braking 2 AT−29
or L position
Valve body faulty Inspect valve body *
transmission
Vehicle does not Manual linkage out of adjustment Adjust linkage AT−26
hold in P Parking lock pawl cam and spring faulty Inspect cam and spring AT−26
AT−17
DIAGNOSIS SYSTEM
DESCRIPTION
1. A self−diagnosis function is built into the electrical
control system. Warning is indicated by the overdrive
OFF indicator light.
HINT: Warning and diagnostic trouble codes can be
read only when the overdrive switch is ON. If OFF, the
overdrive OFF light is lit continuously and will not
blink.
(a) If a malfunction occurs within the vehicle speed sen−
sors (No.1 or 2), solenoids (No.1 or 2), throttle sensor
or engine speed signal, the overdrive OFF indicator
light will blink to warn the driver.
However, there will be no warning of a malfunction
with lock−up solenoid.
(b) The diagnostic trouble code can be read by the
number of blinks of the overdrive OFF indicator light
when terminals TT and E, are connected. (See page AT
−18)
(c) The throttle position sensor or brake signal are not
indicated, but inspection can be made by checking the
voltage at terminal TT of the data link connector 1.
(d) The signals to each gear can be checked by measuring
the voltage at terminal TT of the data link connector 1
while driving.
2. The diagnostic trouble code is retained in memory by
the TCM and due to back−up voltage, is not canceled
out when the engine is turned off. Consequently, after
repair, it is necessary to turn the ignition switch off
and remove the DOME fuse (10A) or disconnect the
TCM connector to cancel out the diagnostic trouble
code. (See page AT−20)
HINT:
S Low battery positive voltage will cause faulty
operation of the diagnosis system. Therefore,
always check the battery first.
S Use a voltmeter and ohmmeter that have an im−
pedance of at least 10 kW/V.
CHECK “O/D OFF” INDICATOR LIGHT
1. Turn the ignition switch ON.
2. The “0/D OFF” light will come on when the O/D
switch is placed at OFF.
3. When the O/D switch is set to ON, the “0/D OFF”
light should go out.
If the “O/D OFF” light flashes when the 0/D switch is
set to ON, the electronic control system is faulty.
AT−18
READ DIAGNOSTIC TROUBLE CODE

1. TURN IGNITION SWITCH AND O/D SWITCH TO ON
Do not start the engine.
HINT: Warning and diagnostic trouble codes can be
read only when the overdrive switch is ON. If OFF, the
overdrive OFF light will light continuously and will not
blink.
2. CONNECT TT AND E1, TERMINALS OF CHECK

CONNECTOR
Using SST, connect terminals TT and E, of the data link
connector 1.
SST 09843−18020
3. READ DIAGNOSTIC TROUBLE CODE

Read the diagnostic trouble code as indicated by the
number of times the 0/D OFF light flashes.
Diagnostic Trouble Code Indication:

S If the system is operating normally, the light will
flash 2 times per second.
S In the event of a malfunction, the light will flash 1
time per second. The number of blinks will equal
the first number and, after 1.5 seconds pause,
the second number of the 2 digit diagnostic trou−
ble code. If there are 2 or more codes, there will
be a 2.5 seconds pause between each.
HINT: In the event of several trouble codes occurring
simultaneously, indication will begin from the smaller
value and continue to the larger.
4. REMOVE SST
AT−19
ECM DATA MONITOR USING

TOYOTA
HAND−HELD−TESTER
1. Hook up the TOYOTA hand−held−tester to the DLC 1.
2. Monitor the ECM data by following the prompts on
the tester screen.
HINT: TOYOTA hand −hsld−tester has a “Snapshot”
function which records the monitored data.
Please refer to the TOYOTA hand − held − tester
operator’s manual.
DIAGNOSTIC TROUBLE CODES
Code No. Light Pattern Diagnosis System

Normal
Severed throttle position sensor or short circuit−
severed wire harness or short circuit
Defective No. 1 vehicle speed sensor (in combination meter)−
Defective No. 2 vehicle speed sensor (in ATM) −
Severed No. 1 solenoid or short circuit−
Severed No. 2 solenoid or short circuit−
Severed lock−up solenoid or short circuit−
Severed timing solenoid or short circuit−
Severed engine speed sensor or short circuit−
Severed ECM and TCM or short circuit−
HINT: If codes 62, 63, 64, or 65 appear, there is an

electrical malfunction in the solenoid.
Causes due to mechanical failure, such as a stuck
valve, will not appear.
AT−20
CANCEL OUT DIAGNOSTIC TROUBLE

CODE
1. After repair of the trouble area, the diagnostic trouble
code retained in memory by the TCM must be cance−
led by removing the DOME fuse (11 0A) for 10 seconds
or more, depending on ambient temperature (the
lower the temperature, the longer the fuse must be
left out) with the ignition switch OFF.
HINT:
S Cancellation can be also done by removing the

battery negative (−) terminal, but in this case
other memory systems will be also canceled out.
S The diagnostic trouble code can be also canceled
out by disconnecting the TCM connector.
S If the diagnostic trouble code is not canceled out,
it will be retained by the TCM and appear along
with a new code in event of future trouble.
2. After cancellation, perform a road test to confirm that
a “normal code” is now read on the O/D OFF light.
TCM TERMINALS STANDARD VALUE
TCM TERMINAL VALUES
MEASUREMENT BY USING TOYOTA BREAK−OUT
−BOX AND TOYOTA HAND−HELD−TESTER
1. Hook up the TOYOTA brake−out−box and TOYOTA

hand−held−tester to the vehicle.
2. Read the TCM input/output values by following the
prompts on the tester screen.
HINT: TOYOTA hand−held−tester has “Snapshot”
function. This record the measured values and is ef−
fective in the diagnosis of intermittent problems.
Please refer to the TOYOTA hand − held − tester/
TOYOTA break − out − box operator’s manual for
furher details.
AT−21
TROUBLESHOOTING FLOW−CHART
HINT:
• If diagnostic trouble code Nos. 41, 42, 61, 62, 63, 64, 65, 86, 88 and are output, the
overdrive OFF indicator light will begin to blink immediately to warn the driver. However, an
impact or shock may cause the blinking to stop; but the code will still be retained in the TCM
memory until canceled out.
• There is no warning for diagnostic trouble code No.64 and 65.
• In the event of a simultaneous malfunction of both No.1 and No.2 vehicle speed sensors, no
diagnostic trouble code will appear and the fail−safe system will not function. However,
when driving in the D position, the transmission will not up−shift from first gear, regardless
of the vehicle speed.
Diagnostic trouble Code 41 (Throttle position sensor circuitry)

Check continuity between ECM connector NG
Check continuity between ECM connector Replace wire harness between ECM
VA terminal and TCM connector VA ter− and TCM.
minal.
Check voltage between ECM connector VA

terminal and ground. Substitute another ECM.
Voltage: 3.5 − 4.5 V
Substitute another TCM.
Diagnostic trouble Code 42 (No. 1 vehicle speed sensor circuitry)
Jack up the vehicle and turn propeller shaft.

Check voltage between TCM connector SP 1
terminal and body ground.
Voltage: 5 V − 12 V
Check No. 1 vehicle speed sensor. Repair or replace No. 1 vehicle speed
(See page BE−48) sensor.
Check wiring between TCM and combination

meter.
AT−22
Diagnostic trouble Code 61 (No.2 vehicle speed sensor circuitry)
Check resistance between TCM connector

SPz+ terminal and SP2− terminal.
Resistance: 620 ± 80 0
Check No.2 vehicle speed sensor, Repair or replace No.2 vehicle speed
(See page AT−39) sensor.
Check wiring between TCM and vehicle

speed sensor.
Diagnostic trouble Code 62 (No. 1 solenoid valve circuitry)
Check resistance of No. 1 solenoid valve at

TCM connector. (See page AT−38)
Remove oil pan and check resistance of No. 1 IV G

solenoid valve connector and body ground. Replace No. 1 solenoid valve.
Resistance: 11 − 15 0
Check wiring between No. 1 solenoid valve

and TCM.
Diagnostic trouble Code 63 (No.2 solenoid valve circuitry)
Check resistance of No. 2 solenoid valve at

TCM connector. (See page AT−38)
Remove oil pan and check resistance of No. 2

solenoid valve connector and body ground. Replace No. 2 solenoid valve.
Resistance: 11 − 150
Check wiring between No.2 solenoid valve

and TCM.
AT−23
Diagnostic trouble Code 64 (Lock−up solenoid valve circuitry)
Check resistance of lock−up solenoid valve NG

at TCM. (See page AT−38)
Remove oil pan and check resistance of No.2

solenoid valve connector and body ground. Replace lock−up solenoid valve.
Resistance: 11 − 15 9
Check wiring between lock−up solenoid valve

and TCM^.
Diagnostic trouble Code 65 (Timing solenoid valve circuitry)
Check resistance of timing solenoid valve at

TCM. (See page AT−38)
Remove the oil pan and check resistance of

timing solenoid valve connector and body
Replace timing solenoid.
ground.
Resistance: 11 − 15W
Check wiring between timing solenoid valve

and TCM.
Diagnostic trouble Code 86 (Engine speed sensor circuitry)
Check continuity between ECM connector

Replace wire harness between ECM
NEO terminal and TCM connector NE ter−
and TCM.
minal.
Check voltage between TCM connector NE

terminal and ground. Substitute another ECM.
Voltage: Less than 5 V

AT−24
Timing retard demand signal

Replace wire harness between TCM
ECT 1 terminal and TCM connector ECT 1 ter− and ECM.
minal.
Check voltage between TCM connector ECT1

terminal and ground. Substitute another TCM.
Voltage: 0 V
Substitute another ECM
Fail safe signal

Replace wire harness between ECM
ECT2 terminal and TCM connector ECT2 ter−
and TCM.
minal.
Disconnect TCM connector. Check voltage

between TCM connector ECT2 terminal and Substitute another TCM.
ground.
Voltage: 2.5 V
Substitute another ECM.

AT−25
PRELIMINARY CHECK
1. CHECK FLUID LEVEL
HINT:
S The vehicle must have driven so that the engine
and transmission are at normal operating temper−
ature.
S Fluid temperature: 70−80_C (158−176_F)
Only use the COOL range on the dipstick as a
rough reference when the fluid is replaced or the
engine does not run.
(a) Park the vehicle on a level surface, set the parking
brake.
(b) With the engine idling, shift the shift lever into all
positions from P to L position and return to P position.
(c) Pull out the transmission dipstick and wipe it clean.
(d) Push it back fully into the tube.
(e) Pull it out and check that the fluid level is on the HOT
range.
If the level is at the low side, add fluid.
Fluid type:
ATF DEXRONr ll
NOTICE: Do not overfill.
2. CHECK FLUID CONDITION
If the fluid smells burnt or is black, replace it as every
manual follows.
(a) Remove the drain plug and drain the fluid.
(b) Reinstall the drain plug securely.
Torque: 27 N−m (280 kgf−cm, 20 ft.bf)
(c) With the engine OFF, add new fluid through the oil
filler tube.
Fluid type:
ATF DEXRONr ll
Capacity:
Total
15.4 liters (16.3 US qts, 13.6 Imp.qts)
Drain and refill
6.0 liters (6.3 US qts, 5.3 Imp.qts)
(d) Start the engine and shift the shift lever into all posi−
tions from P to L position and then shift into P posi−
tion.
(e) With the engine idling, check the fluid level. Add fluid
up to the COOL level on the dipstick.
AT−26
(f) Check the fluid level with the normal operating tem−
perature 70 − 80_ C (158 −176_ F) and add as necessary.
NOTICE: Do not overfill.
3. INSPECT THROTTLE CABLE

(a) Check that the throttle cable is installed correctly and
not bent.
(b) With the throttle valve fully closed, measure the dis−
tance between the end of the boot and stopper on the
cable.
Standard distance:
0 − 1 mm (0 − 0.04 in.)
If the distance is not standard, adjust the cable by the
adjusting nuts.
4. INSPECT TRANSMISSION SHIFT LEVER POSITION
When shifting the shift lever from the N position to
other positions, check that the lever can be shifted
smoothly and accurately to each position and that the
position indicator correctly indicates the position.
If the indicator is not aligned with the correct position,
carry out the following adjustment procedures.
(a) Loosen the nut on the control rod.
(b) Push the control shaft lever fully toward the rear of
the vehicle.
(c) Return the control shaft lever 2 notches to N position.
(d) Set the shift lever to N position.
(e) While holding the shift lever lightly toward the R
position side, tighten the control rod nut.
(f) Start the engine and make sure that the vehicle moves
forward when shifting the lever from the N to D
position and reverse when shifting it to the R position.
5. INSPECT PARK/NEUTRAL POSITION SWITCH
Check that the engine can be started with the shift
lever only in the N or P position, but not in other
positions.
If not as started above, carry out the following adjust−
ment procedures.
(a) Loosen the park/neutral position switch bolts and set
the shift lever to the N position.
(b) Align the groove and neutral basic line.
(c) Hold in position and tighten the bolts.
Torque: 13 N−m (130 kgf−cm, 9ft.lbf)
AT−27
6. INSPECT IDLE SPEED (N POSITION)

Connect tachometer test probe to the check connec−
tor terminal IG , inspect the idle speed.
Idle speed:
650 rpm
AT−28
MANUAL SHIFTING TEST

HINT: With this test, it can be determine whether the
trouble lies within the electrical circuit or is a mechan−
ical problem in the transmission.
1. DISCONNECT SOLENOID WIRE
2. INSPECT MANUAL DRIVING OPERATION
Check that the shift and gear position correspond
with the table below.
HINT: If the L, 2 and D position gear position are
difficult to distinguish, perform the following road
test.
S While driving, shift through the L, 2 and D positions.
Check that the gear change corresponds to the
shift position.
S If any abnormality is found in the above test, the
problem lies in transmission itself.
3. CONNECT SOLENOID WIRE
4. CANCEL OUT DIAGNOSTIC TROUBLE CODE
(See page AT−20)
REFERENCE: Possible gear position in accordance with solenoid operating conditions.
NO. 1 SOLENOID NO.2 SOLENOID BOTH SOLENOIDS

NORMAL MALFUNCTIONING MALFUNCTIONING MALFUNCTIONING
Solenoid Valve Gear Solenoid Valve Gear Solenoid Valve Solenoid Valve Gear
Gear
Position No. 1 Position No. 1 Position No. 1 Position
Position No. 1 No. 2 No. 2 No. 2 No.2
ON 3rd
OFF 1 st (OFF) O/D
(O/D)
OFF O/D
D positon 2nd 3rd (ON) t 1 SO O/D
OFF 3rd 3rd OFF O/D O/D

OFF OFF O/D OFF O/D OFF O/D O/D
OFF ON 3rd 3rd

(OFF) (O/D)
2 position OFF 3rd

2nd 3rd 3rd
(ON) (1 SO
OFF 3rd 3rd OFF 3rd 3rd

OFF 1 st OFF
L position
2nd 2nd
( ): No fail−safe function x : Malfunctions
AT−29
ELECTRONIC CONTROL SYSTEM

PRECAUTION
Do not open the cover or the case of the TCM and
various ECU unless absolutely necessary.− (If the IC
terminals are touched, the IC may be destroyed by
static electricity.)
ELECTRONIC CONTROL CIRCUIT
AT−30
ELECTRONIC CONTROL
COMPONENTS
AT−31
TROUBLESHOOTING FLOW−CHART
Trouble No. 1 No Shifting
Warm up engine
Coolant temp.: 800C (1760F)
S ATF temp.: 50 − 80_C
(122 − 1760F)
Connect a voltmeter to data link connector

1 terminals TT and El. Does TT terminal vol−
tage vary with changes in throttle opening?
Yes
Is voltage between TCM terminals BK and Brake signal
GND as follows. faulty
0 − 1.5 V: Brake pedal released
10 − 14 V: Brake pedal depressed
Yes
S Throttle position signal faulty
S TT terminal wire open or short
Disconnect solenoid wire connector and road Transmission faulty

test. Does the transmission operate in the
respective gear when in the following slop−
ply driving?
D position ..... Overdrive
2 position ..... 2nd gear
L position ..... 1 st gear
Yes
0 −7V S Transmission faulty
Connect solenoid wire connector and road
test. S Solenoid faulty
Does check connector TT terminal voltage rise 0−5V
from 0 V to 7 V in sequence? Proceed to trouble 3 (AT−33)
0
0−2V Are there 10 − 14 V between TCM

terminal 2 − GND when in the D posi−
tion
Yes
Are there 10 − 14 V between TCM terminals
L − GND when in the D position
Yes
S Park/neutral position switch circuit faulty
S Park/neutral position switch faulty
Try another TCM

AT−32
Trouble No.2 Shift point too high or too low
Warn n up engine
ATF temp.: 50 − 80_C
0 22 − 176_F)
Connect a voltmeter to data link connector

1 terminals TT and El. Does TT terminal
votage vary with changes in throttle opening?
Yes
Is voltage between TCM terminals BK and

Brake signal faulty
GND as follows.
4 − 1.5 V: Brake pedal released
10 − 14 V: Brake pedal depressed
Yes
S Throttle position signal faulty

S TT terminal wire open or short
Check voltage between TCM terminals PWR S Faulty TCM

and El. S Faulty transmission
Power pattern: 10 − 14 V
Normal pattern: 0 − 2 V
Faulty pattern select switch system
AT−33
Trouble No.3 No up−shift to overdrive (After warm−up)
Warm up engine
Coolant temp.: 80_C 0 76oF)
(122 − 1760F)
Road test while shifting manually with Faulty transmission

solenoid wire connector disconnected. Is
there overdrive up−shift in the D position
when shifting from L to 2 to D?
Yes
Connect solenoid wire connector, and while 0−7V S Faulty transmission
driving does check connector TT terminal S Faulty solenoid
voltage rise from 0 V to 7 V in sequence?
0−2V Are there 10 − 14 V between TCM
0−5V
terminals Z − GND when in the 0 posi−
tion
Yes
Are there 10 − 14 between TCM terminals

L − GND when in the D position
Yes
S Park/neutral position switch circuit faulty

S Park/neutral position switch faulty
Try another TCM
Is voltage between TCM terminals OD2 and S Faulty O/D switch harness
GND as follows? S Faulty O/D switch
O/D switch turn ON: 10 − 14 V S Faulty transmission
0!D switch turn OFF: 0 − 2 V
Yes
Yes
Is voltage between TCM terminals OD 1 and Try another TCM
G ND as follows?
0 − 3V
Yes
Is voltage between TC M terminals C/C and Faulty cruise control ECU
G ND normal with the cruise control ECU con−
nector pulled out?
S Faulty ECM
S Faulty cruise control wire harness
AT−34
Trouble No.4 No lock−up (After warm−up)
Warm up engine
(122 − 176_F)
Road test S Lock−up solenoid stuck

Yes
Connect a voltmeter to data link connector S Faulty transmission
1 terminals TT and El. Are there 7 or 5 V in S Faulty lock−up mechanism
the lockup position while driving?
Is voltage between TCM connector 8K and Faulty brake signal

GND terminals as follows?
Brake pedal depressed: 10 − 14 V
Brake pedal released: 0 − 1.5 V
Yes
Faulty throttle position signal

AT−35
TERMINAL VOLTAGE INSPECTION

1. INSPECT THROTTLE POSITION SENSOR SIGNAL
(a) Turn the ignition switch to ON. Do not start the
engine.
(b) Connect a voltmeter to data link connector 1
terminals TT and E,
(c) While slowly depressing the accelerator pedal, check

that Tt terminal voltage rises in sequence.
If the voltage does not change in proportion to the
throttle opening angle, there is a malfunction in the
throttle position sensor or circuit..
2. INSPECT BRAKE SIGNAL

(a) Depress the accelerator pedal until the TT terminal
indicates 8 V.
(b) Depress the brake pedal and check the voltage read−
ing from the TT terminal.
Brake pedal depressed ............ 0 V
Brake pedal released ................ 8 V
If not as indicated, there is a malfunction in either the
stop light switch or circuit.
3. INSPECT EACH UP−SHIFT POSITION

(a) Warm up the engine.
Coolant temperature:
80_C (1760 F)
(b) Turn the O/D switch to ’ON’.
(c) Place the pattern select switch in ”Normal” and the
shift lever into the D position.
(d) During a road test (about 10 km/h or 6 mph) check
that voltage at the TT terminal is as indicated below for
each up−shift position.
If the voltage rises from 0 V to 7 V in the sequence
shown, the control system is okay.
The chart on the left shows the voltmeter reading and
corresponding gears.
AT−36
HINT: Determine the gear position by a light shock or

change in engine RPM when shifting. The lock−up
clutch will turn ON only infrequently during normal
3rd and 0/D gear operation. To trigger this action,
press the accelerator pedal to 50% or more of its
stroke. At more than 50%, the voltage may change in
the sequence 2 V−4 V−6 V−7 V.
AT−37
ELECTRONIC CONTROL COMPONENTS

INSPECTION
1. INSPECT VOLTAGE OF TCM

(a) Turn on the ignition switch.
(b) Measure the voltage at each terminal.
Q03115
Terminal Measuring condition Voltage (V)

N position .
Si − GND Stop Vehicle 9 − 14
D position 9 − 14
N position 9 − 14
S2 − GND Stop Vehicle
D position o− 1
SL − GND Stop vehicle 0 .−51.5
ST − GND Stop vehicle o − 1.5
Brake pedal is depressed 7.5 − 14
BK − GND
Brake pedal is released 0 − 1.5
Transfer position is N position o −3
TFN − GND
Transfer position is except N position 9 − 14
+B − GND Stop engine and ignition switch ON 9 − 14
IG − GND Stop engine and ignition switch ON 9 − 14
O/D main switch turned ON 0−3
OD2 − GND
O/D main switch turned OFF 9 − 14
CIC − G ND Stop engine and ignition switch ON 9 − 14
ECT1 − GND Stop engine and ignition switch ON 9 − 14
Engine coolant temperature 55_C 0 31 _F) more than 9 − 14
OD1 − GND
Engine coolant temperature 550C (131 _F) or less 0 −3
SP2+ − SP2− Vehicle moving Pulse generation
SP1 − GND Vehicle moving Pulse generation
NE − GND Engine idling speed Pulse generation
Throttle valve fully closed 0−3
IDL − GND
Throttle valve fully open 9 − 14
Throttle valve fully closed 3.5 − 4.5
V A − G ND
Throttle valve fully open 2.5 − 3.5
AT−38
Terminal Measuring condition Voltage (V)

2 position 7.5 − 14
2 − GND Except 2 position 0 − 1.5
P position 7.5 − 14
P − GND
Except P position 0 − 1.5
L position 7.5− 14
L − GND
Except L position 0 − 1.5
N position 7.5 − 14
N − GND
Except N position o − 1.5
R position 7.5 − 14
R − GND
Except R position 0 − 1.5
DG − GND Engine stop and place ignition key at ON position o − 1.5

ECT2 − GND Engine coolant temperature 80_C 1176_F1 more than 2−3
PWR pattern 7.5 − 14
PWR − GND
NORM pattern 0 − 1.5
ESA 1 − GND Engine idling speed (Engine start after 10 second) 4.5 − 5.5
ESA2 − GND Engine idling speed (Engine start after 10 second) 4.5 − 5.5
ESA3 − GND Engine idling speed (Engine start after 10 second) 4.5−5.5
Transfer position is L4 position 7.5 − 14
L4 − G N D
Transfer position is except L4 position 0 − 1.5
2. INSPECT SOLENOID
(a) Disconnect the connector from TCM.
(b) Measure the resistance between S,, S2, SL, ST and
ground.
Resistance:
11−150
(c) Apply battery positive voltage to each terminal. Check
that an operation noise can be heard from the sole−
noid.
3. CHECK SOLENOID SEALS

If there is foreign material in the solenoid valve, there
will be no fluid control even with solenoid operation.
(a) Check No.1, No.2 and timing solenoid valves.
Check that the solenoid valves do not leak when
low−pressure compressed air is applied.
When supply battery positive voltage to the sole−
noids, check that the solenoid valves open.
AT−39
(b) Check the lock −up solenoid valve.

e Apply 490 kPa (5 kgf/crn2, 71 psi) of compressed
air, check that the solenoid valve opens.
Apply battery positive voltage to the solenoid,
check that the solenoid valve does not leak the air.
If malfunction is found during voltage inspection (step
1.), inspect the components listed below.
4. INSPECT THROTTLE POSITION SENSOR

Using an ohmmeter, check the resistance between
terminals.
Throttle valve
condition Resistance (kQ)
Terminal
Fully closed 2.3 kS2 or less
IDL − E2
Open Infinity
VC − E2 2.5− 5.9
Fully closed 0.2 − 5.7
VTA − E2
Fully open 2.0− 10.2
5. INSPECT NO.2 VEHICLE SPEED SENSOR

(a) Jack up the rear wheel on one side.
(b) Connect an ohmmeter between the terminals.
(c) Spin the wheel and check that the meter needle de−
flects from 0 to ^W.
6. INSPECT NO.1 VEHICLE SPEED SENSOR
(SEE PAGE BE−48)
7. INSPECT PATTERN SELECT SWITCH

Using an ohmmeter, check the continuity of terminals
for each switch position.
HINT: As there are diodes inside, be careful of the
tester probe polarity.
Terminal
Pattern
PW R
NORM
V02104
AT−40
8. INSPECT O/D SWITCH

Using an ohmmeter, check the continuity of the termi−
nals for each switch position.
SW position
OFF
9. INSPECT PARK/NEUTRAL POSITION SWITCH

Check that there is continuity between terminals.
: Continuity
10. INSPECT ENGINE COOLANT TEMPERATURE

SENSOR
(See page EG−300)
AT−41
A / T FLUID TEMPERATURE
WARNING SYSTEM CIRCUIT
11. INSPECT A / T FLUID TEMPERATURE WARNING

LIGHT
(a) Disconnect the connector from the temperature
sensor. Connect terminal of the wire harness side
connector and body ground.
(b) Turn the ignition switch ON, check that the light goes
on.
If warning light does not light, test the bulb.
12. INSPECT A/T FLUID TEMPERATURE SENSOR

Check that there is continuity at the temperature of
145_ C −155_ C (325_ F − 343_ F).
If continuity is not as specified, replace the sensor.
AT−42
STALL TEST
The objective of this test is to check the overall performance of the transmission and engine by
measuring the stall speeds in the D and R positions.
NOTICE:
S Perform the test at normal operating fluid temperature 50−$0_C (122−116_F).
S Do not continuously run this test longer than 5 seconds.
S To ensure safety, conduct this test in a wide, clear, level area, which provides good traction.
S The stall test should always be carried out in pairs. One should observe the conditions of wheels
or wheel stoppers outside the vehicle while the other is performing the test.
MEASURE STALL SPEED
(a) Warm up the transmission fluid.
(b) Chock the front and rear wheels.
(c) Connect a tachometer to the engine.
(d) Fully apply the parking brake.
(e) Keep your left foot pressed firmly on the brake pedal.
(f) Start the engine.
(g) Shift into the D position. Step all the way down on the accelerator pedal with your right foot.
Quickly read the stall speed at this time.
NOTICE: Release the accelerator pedal and stop test if the rear wheels begin to rotate before the
engine speed reaches specified stall speed.
Stall speed:
2,150+150 rpm
(g) Perform the same test in R position.
Quickly read the stall speed at this time.
Stall speed:
2,150+150 rpm
EVALUATION
(a) If the stall speed is the same for both positions but lower than specified value:
S Engine output may be insufficient
S Stator one−way clutch is not operating properly
HINT: If more than 600 RPM below the specified value, the torque converter clutch could be
faulty.
(b) If the stall speed in D position is higher than specified:
S Line pressure too low
S Forward clutch slipping
S No.2 one−way clutch not operating properly
S 0/D one−way clutch not operating properly
(c) If the stall speed in R position is higher than specified:
S Direct clutch slipping
S First and reverse brake slipping
(d) If the stall speed in both R and D positions are higher than specified:
S Improper fluid level
AT−43
AT−44
TIME LAG TEST

When the shift lever is shifted while the engine is idling, there will be a certain time elapse or lag
before the shock can be felt. This is used for checking the condition of the 0/D direct clutch,
forward clutch, direct clutch and first and reverse brake.
NOTICE:
S Perform the test at normal operating fluid temperature 50−80_C (122−176_F).
S Be sure to allow one minute interval between tests.
S Make three measurements and take the average value.
MEASURE TIME LAG
(a) Fully apply the parking brake.
(b) Start the engine and check the idle speed.
Idle speed:
650 RPM (N position)
(c) Shift the shift lever from N to D position. Using a stop watch, measure the time it takes from
shifting the lever until the shock is felt.
Time lag:
Less than 0.7 seconds
(d) In same manner, measure the time lag for N−iR.
Time lag:
Less than 1.2 seconds
EVALUATION
(a) If N−iD time lag is longer than specified:
S Forward clutch worn
(b) If N−iR time lag is longer than specified:
S Direct clutch worn
S First and reverse brake worn
AT−45
AT−46
HYDRAULIC TEST
PREPARATION
(a) Warm up the transmission fluid.
(b) Remove the transmission case test plug and connect the hydraulic pressure gauge.
SST 09992−00094 (Oil pressure gauge)
NOTICE:
S Perform the test at normal operating fluid temperature 50−$0_ C (122−176_ F).
S The line pressure test should always be carried out in pairs. One should observe the conditions of
wheels or wheel stoppers outside the vehicle while the other is performing the test.
MEASURE LINE PRESSURE
(a) Fully apply the parking brake and chock the 4 wheels.
(b) Start the engine and check idling RPM.
(c) Keep your left foot pressed firmly on the brake pedal and shift into D position.
(d) Measure the line pressure when the engine is idling.
(e) Press the accelerator pedal all the way down. Quickly read the highest line pressure when engine
speed reaches stall speed.
NOTICE: Release the accelerator pedal and stop test if the rear wheels begin to rotate before the
engine speed reaches specified stall speed.
(f) In the same manner, perform the test in R position.
Line pressure:
Condition D position R position

461− 520 kPa 657−843 kPa
Idling (4.7−5.3 kgf/cm2, 68−77 psi)
(6.7−8.6 kgf/cml, 97−125 psi)
971 −1,225 kPa 1,618−1,853 kPa
Stall (16.5−18.9 kgf/cm2, 235−274 psi)
(9.9−12.5 kgf/emt, 144−181 psi)
If the measured pressures are not up to specified values, recheck the throttle cable adjustment
and perform a retest.
AT−47
EVALUATION
(a) If the measured values at all positions are higher than specified:
S Throttle cable out of adjustment
S Throttle valve defective
S Regulator valve defective
(b) If the measured values at all positions are lower than specified:
S Throttle valve defective
S Throttle cable out of adjustment
S Regulator valve defective
S Oil pump defective
S O/D direct clutch defective
(c) If pressure is low in the D position only:
S D position circuit fluid leakage
S Forward clutch defective
(d) If pressure is low in the R position only:
S R position circuit fluid leakage
S Direct clutch defective
S First and reverse brake defective
AT−48
ROAD TEST
NOTICE: Perform the test at normal operating fluid tem−
perature 50 − 80_ C (122 −176_ F).
1. D POSITION TEST IN NORM AND PWR PATTERN
POSITIONS
Shift into the D position and hold the accelerator
pedal constant at the full throttle valve opening posi−
tion.
Check the following:
(a) 1 −2, 2−3 and 3−O/D up−shifts should take place,
and shift points should conform to those shown in the
automatic shift schedule.
Conduct a test under both Normal and Power pat−
terns.
HINT: There is no O/D up−shift or lock−up when the
coolant temperature is below 55_ C (131 _ F).
EVALUATION
(1) If there is no 1−2 up−shift:
S No.2 solenoid is stuck.
S 1−2 shift valve is stuck.
(2) !f there is no 2−3 up−shift:
S No.1 solenoid is stuck.
(3) If there is no 3−0/D up−shift:
(4) If the shift point is defective:
S Throttle valve, 1 − 2 shift valve, 2−3 shift valve,
S 3−4 shift valve etc., are defective.
(5) If the lock−up is defective:
S Lock−up solenoid is stuck.
S Lock−up control valve is stuck.
S Lock−up signal value is stuck.
(b) In the same manner, check the shock and slip at the −2, 2−
3, and 3−O/D up−shifts.
EVALUATION
If the shock is excessive:
S Line pressure is too high.
S Accumulator is defective.
S Check ball is defective.
AT−49
(c) Run at the D position lock −up or O/D gear and check
for abnormal noise and vibration.
HINT: The check for the cause of ahnormal noise and
vibration must be made with extreme care as it could
also be due to loss of balance in the propeller shaft,
differential, torque converter clutch, etc.
(d) While running in the D position, 2nd, 3rd and O/D

gears, check to see that the possible kick−down
vehicle speed limits for 2−1, 3−2 and O/D−3 kick−
downs conform to those indicated on the automatic
shift schedule.
(e) Check for abnormal shock and slip at kick−down.
(f) Check for the lock−up mechanism.

(1) Drive in D position, 0/D gear, at a steady speed
(lock−up ON) of about 95 km/h (59 mph).
(2) Lightly depress the accelerator pedal and check
that the engine RPM does not change abruptly.
If there is a big jump in engine RPM, there is no lock−
up.
2. 2 POSITION TEST
Shift into the 2 position and, while driving with the
accelerator pedal held constantly at the full throttle
valve opening position, push in one of the pattern
selectors and check on the following points.
(a) Check to see that the 1−2 up−shift takes place and
that the shift point conforms to that shown on the
automatic shift schedule.
HINT: There is no 0/D up−shift and lock−up in the 2
position.
(b) While running in the 2 position and 2nd gear, release
the accelerator pedal and check the engine braking
effect.
EVALUATION
If there is no engine braking effect:
S Second coast brake is defective.
AT−50
(c) Check for abnormal noise at acceleration and deceler−

ation, and for shock at up−shift and down−shift.
3. L POSITION TEST
(a) While running in the L position, check to see that
there is no up−shift to 2nd gear.
(b) While running in the L position, release the accelera−

tor pedal and check the engine braking effect.
EVALUATION
If there is no engine braking effect:
S First and reverse brake is defective.
(c) Check for abnormal noise during acceleration and

deceleration.
4. R POSITION TEST
Shift into the R position and, while starting at full
throttle, check for slipping.
AT−51
5. P POSITION TEST
Stop the vehicle on a gradient (more than 5_) and after
shifting into the P position, release the parking brake.
Then check to see that the parking lock pawl holds the
vehicle in place.
AT−52
AUTOMATIC SHIFT SCHEDULE
km/h (mph)
Throttle valve opening 100% 5% 100%

Lock−up Lock−up
Gear position 1 −2 2− 3 3− O/D O/D− 3 3−2 2−1
ON OFF
52−58 106−117 so−s6 55−80 145−15fi 98−104 42−47

Normal mode 152−163
(32−36) ( ss−73 ) (37−41) (34−37) (90−97) (61−65) t26−29t
(94−101)
D position
52−58 106−117 152−163 88−94 68−74 145−156 98−104 42−47
Power mode (32−36) (66−73) (94−101) (55−58) (42−46) (90−97) (61−65) (2fi−29)
Normal mode 52−58 116−127 56−65

2 position
Power mode (32−36) (72−79) (37−40)
L position Normal mode

Power mode
AT−53
TROUBLESHOOTING MATRIX CHART

Use the table below to help you find the cause of the problem. The numbers indicate the priority
of the likely cause of the problem. Check each part in order. If necessary, replace these parts.
Remark *: Refer to ’94 A442F Automatic Transmission Repair Manual.
(ON−VEHICLE)
AT−54
See page
OFF−vehicle repair matrix chart

Parts
Name
Accumulator control valve

Low coast modulator valve
2 − 3 shift timing valve
Lock−up control valve

Reverse control valve
Lock−up signal valve

Lock−up solenoid
Co exhaust valve
B 1 accumulator
C2 accumulator
Bo accumulator
Modulator valve
1 − 2 shift valve
2 − 3 shift valve
Timing solenoid
3 − 4 shift valve
C, accumulator
No. 1 solenoid
No. 2 solenoid
Throttle cable
Manual valve
Check ball
Trouble
TC M
Does
.. . not move in any forward position
Does not move in reverse
Does not move in any position
1rst − 2rd
No up−shift 2nd − 3rd
3rd − O/D
O/D − 3rd
No down−shift 3rd − 2nd
....
2rd − 1rst
Shift point too high or two low
”N” − “R”
”N” − “D”
”N” − “D” , ”N” − “R”
Harsh 1rst − 2rd
engagement 2nd − 3rd
3rd − O/D
1rst − 2nd − 3rd − O/D
O/D − 3rd
3rd − 2nd
Forward & Reverse
“R” position
1rst
Slip
2nd
3rd
O/D
No engine 1st (”L” position)
braking 2nd (”2” position)
.... .
No kick−down
..,Poor
. . acceleration
No lock−up
AT−54
RemarkK: Refer to ’94 A442F Automatic Transmission Repair Manual.
(OFF−VEHICLE)
AT−53
AT−69
See page
1st and reverse brake (B3)
No.2 one−way clutch (F2)

ON−Vehicle matrix chart
O/D one−way clutch (Fo)
Parts
Torque converter clutch

Name
O/D direct clutch (Co)
Front planetary gear

Rear planetary gear
Front clutch (C1)
Rear clutch (C2)
2nd brake (B2)
O/D brake (Bo)
Oil Pump
Trouble
Does not move in any forward position

Does not move in reverse position
Does not move in any position
lSt−2nd
No up−shift 2nd−3rd
3rd − O/D
O/D→3rd
No down−shift 3rd−2nd
2nd −1 st
Shift point too high or too low
“N”→”R”
“N”→”D”
“N”→”D”, “N”→”R”
Harsh 1 st−2nd
engagement 2nd→3rd
3rd→O/D
1 st →2nd→3rd →OID
O/D→3rd
3rd−2nd
Forward & Reverse
”R” position
1 st
Slip
2nd
3rd
O/D
No engine 1st (”L” position)
braking 2nd (”2” position)
. .. .
No kick−down
Poor acceleration
No lock−up

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AT−14

AUTOMATIC TRANSMISSION − TROUBLESHOOTING

Read Diagnostic Trouble Code Bad

Preliminary Check Bad

Manual Shifting Test

Stall Test, Time Lag Test and

Repair or Replace Repair Transmission

Problem Possible cause Remedy Page

Drag, binding or Manual linkage out of adjustment Adjust linkage AT−26

Problem Possible cause Remedy Page

Solenoid valve faulty Inspect solenoid valve AT−38, 39

Solenoid valve faulty Inspect solenoid valve AT−38, 39

READ DIAGNOSTIC TROUBLE CODE

2. CONNECT TT AND E1, TERMINALS OF CHECK

3. READ DIAGNOSTIC TROUBLE CODE

Diagnostic Trouble Code Indication:

ECM DATA MONITOR USING

DIAGNOSTIC TROUBLE CODES

Code No. Light Pattern Diagnosis System

HINT: If codes 62, 63, 64, or 65 appear, there is an

CANCEL OUT DIAGNOSTIC TROUBLE

S Cancellation can be also done by removing the

1. Hook up the TOYOTA brake−out−box and TOYOTA

Diagnostic trouble Code 41 (Throttle position sensor circuitry)

Check voltage between ECM connector VA

Substitute another TCM.

Diagnostic trouble Code 42 (No. 1 vehicle speed sensor circuitry)

Jack up the vehicle and turn propeller shaft.

Substitute another TCM.

Check wiring between TCM and combination

Diagnostic trouble Code 61 (No.2 vehicle speed sensor circuitry)

Check resistance between TCM connector

Substitute another TCM.

Check wiring between TCM and vehicle

Check resistance of No. 1 solenoid valve at

Substitute another TCM.

Remove oil pan and check resistance of No. 1 IV G

Check wiring between No. 1 solenoid valve

Diagnostic trouble Code 63 (No.2 solenoid valve circuitry)

Check resistance of No. 2 solenoid valve at

Substitute another TCM.

Remove oil pan and check resistance of No. 2

Check wiring between No.2 solenoid valve

Diagnostic trouble Code 64 (Lock−up solenoid valve circuitry)

Check resistance of lock−up solenoid valve NG

Substitute another TCM.

Remove oil pan and check resistance of No.2

Check wiring between lock−up solenoid valve

Diagnostic trouble Code 65 (Timing solenoid valve circuitry)

Check resistance of timing solenoid valve at

Substitute another TCM.

Remove the oil pan and check resistance of

Check wiring between timing solenoid valve

Diagnostic trouble Code 86 (Engine speed sensor circuitry)

Check continuity between ECM connector

Check voltage between TCM connector NE

Substitute another TCM.

Timing retard demand signal

Check continuity between ECM connector