TOYOTA CAMRY V20 1986 Service Information

TROUBLESHOOTING (A540E, A540H)
Basic Troubleshooting
Before troubleshooting an ECT, 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 along with the general
troubleshooting chart on the following pages should speed the procedure.
Stall Test, Time Lag Test and
Hydraulic Test Electrical Control System CheckRead Diagnostic Code
(See page AT± 191)
Manual Shifting Test
(See page AT±202) Preliminary Check
(See page AT±199)
Repair Transaxle
Repair or ReplaceRepair
or
Replace
OK
OKBadBad Bad
Bad
Bad
± AUTOMATIC TRANSAXLETroubleshooting (Basic Troubleshooting) (A540E and A540H)AT±186

Shift cable out of adjustment
Valve body or primary regulator
faulty
Parking lock pawl faulty
Torque converter faulty
Converter drive plate broken
Oil pump intake screen blocked
Transaxle faulty
Shift cable out of adjustment
Throttle cable out of adjustment
Valve body faulty
Solenoid valve faulty
Transaxle faulty Throttle cable out of adjustment
Valve body or primary regulator faulty
Accumulator pistons faulty
Transaxle faultyInspect parking lock pawl
Replace torque converter
Replace drive plate
Clean screen
Disassemble and inspect
transaxle
Adjust shift cable
Adjust throttle cable
Inspect valve body
Inspect solenoid valve
Disassemble and inspect
transaxle Delayed 1±2, 2±3 or
3±O/D up±shift, or
down±shifts from
O/D±3 or 3±2 and
shifts back to O/D or 3Replace fluid
Replace torque converter
Disassemble and inspect
transaxle
Adjust shift cable
Inspect valve body
Disassemble and inspect
transaxle
Adjust shift cable
Inspect valve body
Disassemble and inspect
transaxle Shift cable out of adjustment
Valve body faulty
Transaxle faultyShift cable out of adjustment
Manual valve and lever faulty
Transaxle faulty
Inspect electronic control
Inspect valve body
Inspect solenoid valveInspect accumulator pistons
Disassemble and inspect
transaxle
General Troubleshooting
Electronic control faulty
Valve body faulty
Solenoid valve faultyFluid contaminated
Torque converter faulty
Transaxle faulty
Slips on 1±2, 2±3
or
3±O/D up±shift, or
slips or shudders
on accelerationVehicle does not move in
any forward range or
reverse
Drag, binding or tieup on
1±2, 2±3 or 3±
O/D up±shiftHarsh engagement into
any drive range
AT±201
AT±201
AT±308
AT±218
AT±236 Adjust throttle cable
Inspect valve body
AT±219 Adjust shift cable
Inspect valve body
Shift lever position
incorrect Fluid discolored
or smells burntAT±200
AT±381
AT±236
AT±203
AT±308
AT±218AT±201
AT±308
AT±236
AT±201
AT±308
AT±236AT±219 AT±201
AT±308AT±392
AT±381AT±201
AT±308
AT±403
AT±236 Possible cause
Problem
Remedy
1± AT±236A540 H A540EPage
± AUTOMATIC TRANSAXLETroubleshooting (Basic Troubleshooting) (A540E and
A540H)AT±187

Throttle cable out of adjustment
Throttle cable and cam faulty
Accumulator pistons faulty
Valve body faulty
Transaxle faultyAdjust throttle cable
Inspect throttle cable and cam
Inspect accumulator pistons
Inspect valve body
Disassemble and inspect
transaxle
General Troubleshooting (Cont'd)
Inspect throttle cable
Inspect valve body
Disassemble and inspect
transaxle
Inspect solenoid valve
Inspect electronic control
Inspect electronic control
Inspect valve body
disassemble and inspect
transfer
Disassemble and inspect
center differential clutch Inspect solenoid valve
Inspect electronic control
Inspect valve body
Disassemble and inspect
transaxle Inspect electronic control
Inspect valve body
Inspect solenoid valve
Disassemble and inspect
transaxle
Solenoid valve faulty
Electronic control faulty
Valve body faulty
Transaxle faulty Electronic control faulty
Valve body faulty
Solenoid valve faulty
Transaxle faulty
Shift cable out of adjustment
Parking lock pawl and spring faultyInspect solenoid valve
Inspect electronic control
Inspect valve body Inspect valve body
Inspect solenoid valve
Inspect electronic control
Solenoid valve faulty
Electronic control faulty
Valve body faulty
Electronic control faulty
Valve body faulty
Transfer faulty Valve body faulty
Solenoid valve faulty
Electronic control faulty
Throttle cable faulty
Valve body faulty
Transaxle faulty
Solenoid valve faulty
Electronic control faulty Down±shift occurs too
quickly or too late while
coasting
Adjust shift cable
Inspect cam and spring No down±shift when
coasting
Hydraulic multiplate clutch faultyAT±218
AT±203
AT±308
AT±236 AT±203
AT±308
AT±218
AT±236
AT±219


 No engine braking in 2
or L range No lock±up in 2nd,
3rd or O/D
No center differential
Control No O/D±3, 3±2
or
2±1 kick±down

AT±219

Vehicle does not hold
in P rangeAT±308
AT±218
AT±203
AT±218
AT±203
AT±308 AT±201
AT±308
AT±236 AT±403
AT±308
AT±236
AT±203
AT±368
AT±343 AT±219


AT±219
 Harsh down±shift
AT±201
AT±392 AT±201
AT±201
AT±218
AT±203AT±219
 Possible cause
ProblemRemedy
AT±335 A540H
A540EPage
± AUTOMATIC TRANSAXLETroubleshooting (Basic Troubleshooting) (A540E and
A540H)AT±188

( ) 1: No fail±safe function X: Malfunctions
HINT: (A540H) When any one of the speed sensors (front or rear) or center differential control sole-
noid valves (No. 1 or No. 2) malfunction, the ECT ECU stops center differential control and main-
tains the center differential in a free condition.
Operating Mechanism for Each Gear (A540E A540H)
1. CLUTCH BRAKE AND ONE±WAY CLUTCH
A540E, A540H
Down±shift only ± no up±shift
2. SOLENOID SYSTEM
Possible gear positions in accordance with solenoid operating conditions.
A540E, A540H
NO. 2 SOLENOID
MALFUNCTIONING NO. I SOLENOID
MALFUNCTIONINGBOTH SOLENOIDS
MALFUNCTIONING Shift lever
positionGear position
NORMAL
D rangeParking
2 range
L rangeReverse
Neutral
Range
2nd3 rd
O/D
2nd1st
1st 1st2nd
3rd
± AUTOMATIC TRANSAXLETroubleshooting (Operating Mechanism for Each Gear
(A540E and A540H)AT±189

Diagnosis System
DESCRIPTION
1. A self±diagnosis function is. built into the electrical control
system. Warning is indicated by the overdrive OFF indicator.
HINT: Warning and diagnostic codes can be read only when
the overdrive switch is ON. If OFF, the overdrive OFF
indicator is lit continuously and will not blink.
(a) If a malfunction occurs within the speed sensors or sole-
noids, the overdrive OFF light will blink to warn the driver.
However, there will be no warning of a malfunction with
lock±up solenoid.
W The diagnostic code can be read by the number of
blinks of the overdrive OFF indicator when terminals
Tt and E1 are short±circuited. (See page AT± 191)
(c) The throttle position sensor or brake signal are not indicated,
but inspection can be made by checking the voltage at ter-
minal Tt of the check connector.
(d) The signals to each gear can be checked by measuring the
voltage at terminal Tt of the check connector while driving.
2. The diagnostic (malfunction) code is retained in memory by the
ECU 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 fuse EFI (15A)
(A540E) or DOME (20A)
(A540H) or disconnect the Engine and ECT ECU (A540E)
or ECT ECU (A540H) connector to cancel out the diagnostic
(malfunction) code. (See page AT±192)
HINT:
wLow battery voltage will cause faulty operation of the diag-
nosis system. Therefore, always check the battery first.
wUse a voltmeter and ohmmeter that have an impedance of
at least 10 k
/V.
CHECK O/D OFF INDICATOR LIGHT
1. Turn the ignition switch ON.
2. The O/D OFF light will come on when the O/D switch
placed at OFF.
3. When the O/D switch is set to ON, the O/D OFF light should go
out.
If the O/D OFF light flashes when the O/D switch is set to
ON, the electronic control system is faulty.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±190

wn the event of a malfunction, the light will blink once
every 0.5 seconds. The number of blinks will equal
the first number and, after 1.5 seconds pause, the
second number of the two digit diagnostic code. If
there are two or more codes, there will be a 2.5 sec-
onds 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
SST 09843±18020
READ DIAGNOSTIC CODE
1. TURN IGNITION SWITCH AND O/D SWITCH TO ON
Do not start the engine.
HINT: Warning and diagnostic 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. SHORT Tt TERMINAL CIRCUIT OF CHECK
CONNECTOR
Using SST, short terminals Tt and E1 of the check connector.
SST 09843±18020
3. READ DIAGNOSTIC CODE
Read the diagnostic code as indicated by the number of
times the O/D OFF light flashes.
(Diagnostic Code Indication)
wIf the system is operating normally, the light will blink
once every 0.25 seconds.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±191

AT4B'
HINT: If codes 62, 63, 64, 73 or 74 appear, there is an electrical malfunction in the solenoid.
Causes due t mechanical failure, such as a stuck valve, will not appear.
If codes 44 and 61 appear, check the both (vehicle and rear wheel) speed sensors.
AT2020
HINT: If codes 62, 63 or 64 appear, there is an electrical malfunction in the solenoid. Causes due
to mechanical failure, such as a stuck valve, will not appear.
Severed No. 2 center differential control solenoid valve or short circuit
± severed wire harness or short circuit. Defective rear wheel speed sensor (in transfer left case) ±
severed wire harness or short circuit
Defective vehicle speed sensor (in differential carrier cover)
severed wire harness or short circuit
Severed No. 1 center differential control solenoid valve or short
circuit ± severed wire harness or short circuit. Defective No. 1 speed sensor (in combination meter) ±
severed wire harness or short circuit
DIAGNOSTIC CODES.
(A540E)
Severed lock±up solenoid or short circuit ±
severed wire harness or short circuit Severed lock±up solenoid or short circuit ±
severed wire harness or short circuitDefective No. 2 speed sensor (in ATM) ±
severed wire harness or short circuit
Severed No. t solenoid or short circuit ±
severed wire harness or short circuit
Severed No. 2 solenoid or short circuit ±
severed wire harness or short circuit Severed No. 1 solenoid or short circuit ±
severed wire harness or short circuit
Severed No. 2 solenoid or short circuit ±
severed wire harness or short circuitDiagnosis System
Diagnosis System Light Pattern
Light Pattern
(A540H)
Code No.
Code
No.
Normal Normal
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±192

CANCEL OUT DIAGNOSTIC CODE
1. After repair of the trouble area, the diagnostic code
retained in memory by the Engine and ECT ECU (A540E)
or ECT ECU (A540H) must be canceled by removing the fuse EFI
(15A) (A540E) or DOME (20A) (A540H) 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.
wHINT:Cancellation can be also done by removing the battery
negative (±) terminal, but in this case other memory systems
(engine control system diagnosis memory,
clock. ETR, etc.) will also be canceled out
wThe diagnostic code can be also canceled out by disconnect-
ing the Engine and ECT ECU (A540E) or ECT
ECU (A540H) connector.
wIf the diagnostic code is not canceled out, it will be retained
by the Engine and ECT ECU (A540E) or ECT
ECU (A540H) and appear along with a new code in
event of future trouble.
2. After cancellation, perform a road test to confirm that a
ºnormal codeº is now read on the O/D OFF indicator.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±193

TROUBLESHOOTING FLOW±CHART (A540E)
HINT:
wIf diagnostic code Nos. 42, 61, 62 or 63 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 Engine and ECT ECU memory until canceled out.
wThere is no warning for diagnostic code No. 64.
wIn the event of a simultaneous malfunction of both No. 1 and No. 2 speed sensors, no diagnostic
code will appear and the fail±safe system will not function. However, when driving in the D range,
the transaxle will not up±shift from first gear, regardless of the vehicle speed.
Check continuity between Engine and ECT
ECU connector SP, terminal and body ground.
(See page AT±216)
Check continuity between Engine and ECT
ECU connector SP2 terminal and body ground.
(See page AT±216)
1. Diagnostic code 42 (No. 1 speed sensor circuitry)
Check wiring between Engine and ECT ECU
and No. 2 speed sensor. Check wiring between Engine and ECT ECU
and combination meter.
2. Diagnostic code 61 (No. 2 speed sensor circuitry)
Check No. 2 speed sensor.
(See page AT±234) Substitute another Engine and ECT ECU.
Substitute another Engine and ECT ECU.Repair or replace No. 1 speed sensor.
Repair or replace No. 2
speed sensor. Check No. 1 speed sensor.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±194

Remove the oil pan and check resistance of
No. t solenoid valve connector and body ground.
Resistance: 11 ± 1 S
Remove the oil pan and check resistance of lock±
up solenoid valve connector and body ground.
Resistance: 11 ± 15 Remove the oil pan and check resistance of
No. 2 solenoid valve connector and body ground.
Resistance: 11 ± 15
Check resistance of lock±up solenoid valve at
Engine and ECT ECU connector.
(See page AT±216) Check resistance of No. 2 solenoid valve at
Engine and ECT ECU connector.
(See page AT±216) Check resistance of No. 1 solenoid valve at
Engine and ECT ECU connector
(See page AT±216)
Replace No. 1 and No. 2 solenoid
valves.
HINT: No. 1 and No. 2 solenoid valves
make a set.Replace No. 1 and No. 2 solenoid
valves.
HINT: No. 1 and No. 2 solenoid valves
make a set.
Check wiring between lock±up solenoid valve and
Engine and ECT ECU.Check wiring between No. 2 solenoid valve and
Engine and ECT ECU.Check wiring between No. 1 solenoid valve and
Engine and ECT ECU.
5. Diagnostic code 64 (Lock±up solenoid valve circuitry)3. Diagnostic code 62 (No. 1 solenoid valve circuitry)
4. Diagnostic code 63 (No. 2 solenoid valve circuitry)
Substitute another Engine and ECT ECU.
Substitute another Engine and ECT ECU.Substitute another Engine and ECT ECU.
Replace lock±up solenoid valve.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±195