warning light TOYOTA CAMRY V20 1986 Service Information

Diagnosis System (A140E)
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 (No.
1 or 2) or solenoids (No. 1 or 2), the overdrive OFF
light will blink to. warn the driver. .
However, there will be no warning of a malfunction with
lock±up solenoid.
(b) 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±17)
tc) The throttle position sensor or brake signal are not indi-
cated, but inspection can be made by checking the voltage at
terminal Tt of the check connector (diagnosis).
(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
CPU 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) or
disconnect the ECT computer connector to cancel out the diag-
nostic (malfunction)
code. (See page AT±18)
HINT:
wLow battery voltage will cause faulty operation of the diag-
nosis system. Therefore, always check the battery first.
w Use a voltmeter and ohmmeter that have an impedance
of at least 10 k 11 IV.
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 is
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) (A140E)AT±16

wIn the event of a malfunction, the fight will blink once every
0.5 seconds. The number of blinks will equal the first num-
ber 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 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
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 ECT TERMINAL CIRCUIT OF CHECK
CONNECTOR
Using a SST, short terminals Tt and E1 of the check
connector.
SST 09843±18020
(Diagnostic Code Indication)
wIf the system is operating normally, the light will
blink once every 0.25 seconds. 3. READ DIAGNOSTIC CODE
Read the diagnostic code as indicated by the number
of times the O/D OFF indicator flashes.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A140E)AT±17

TROUBLESHOOTING FLOW±CHART
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 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.
1. Diagnostic code 42 (No. 1 speed sensor circuitry)
Check continuity between ECT ECU
connector SP, terminal and body ground.
(See page AT±32)
Check continuity between ECT ECU
connector SP2 terminal and body ground.
(See page AT±33)
Check wiring between ECT ECU and No. 2
speed sensor.Check wiring between ECT ECU and
combination meter.
2. Diagnostic code 61 (No. 2 speed sensor circuitry
Repair or replace No. 1 speed
sensor.
Check No. 2 speed sensor.
(See page AT±35)Repair or replace No. 2
speed sensor. Substitute another ECT ECU.
Substitute another ECT ECU.Check No. 1 speed sensor.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A140E)AT±19

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

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

TROUBLESHOOTING FLOW±CHART (A540H)
HINT:
wIf diagnostic code Nos. 44, 61, 62, 63, 73 or 74 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 ECT ECU memory until canceled out.
wThere is no warning for diagnostic code No. 64.
wIn the event of a simultaneous malfunction of both vehicle and rear 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.
1. Diagnostic code 44 (Rear speed sensor circuitry)
Check continuity between ECT ECU NC
Check continuity between ECT ECU
connector RR+ terminal and RR± terminal.
(See page AT±217)
Check continuity between ECT ECU
connector FR+ terminal and FR± terminal.
(See page AT±217)
Check wiring between ECT ECU and vehicle
speed sensor. Check wiring between ECT ECU and rear
wheel speed sensor.
2. Diagnostic code 61 (Vehicle speed sensor circuitry)Repair or replace rear wheel speed
sensor. Check rear wheel speed sensor.
(See page AT±221)
Check vehicle speed sensor.
(See page AT±221)Repair or replace vehicle
speed sensor. Substitute another ECT ECU. Substitute another ECT ECU.
± AUTOMATIC TRANSAXLETroubleshooting (Diagnosis System) (A540E and A540H)AT±196

Fusible link blown
Headlight control relay faulty
Light control/dimmer switch faulty
Daytime running light relay faulty
(CANADA)
Headlight dimmer relay faulty
(CANADA)
Wiring or ground faulty
Replace fuse and check for short
Replace fusible fink
Check relay
Check switch
Check relay
Repair as necessary TAIL fuse blown
Fusible link blown
Taillight control relay faulty
Light control switch faulty
Daytime running light relay faulty
(CANADA)
Wiring or ground faulty Light control/dimmer switch faulty
Daytime running light relay faulty
(CANADA)
Headlight dimmer relay faulty
(CANADA)
Wiring or ground faultyReplace fusible link
Check relay
Check switch
Check relay
Check relay
Repair as necessary
Replace fuse and check for short
Check flasher
Check switch
Repair as necessary
Replace fuse and check short
Check flasher
Check switch
Repair as necessary HAZ±HORN fuse blown
Turn signal flasher faulty
Hazard warning switch faulty
Wiring or ground faultyCheck switch
Check relay
Check relay
Repair as necessary
Replace fuse and check for short
Adjust or replace switch
Repair as necessary
TURN fuse blown
Turn signal flasher faulty
Turn signal switch faulty
Wiring or ground faulty
LIGHTING
Troubleshooting
STOP fuse blown
Stop light swtich faulty
Wiring or ground faulty Light bulb burned out
Socket, wire or ground faulty
High beam headlights or
headlight flashers do not
operate
Light control rheostat faulty
Wiring or ground faulty Instrument lights do not
light (taillights light)Tail, parking and
license light do not
light
Turn signal switch faulty
Wiring or ground faulty
Hazard warning lights do
not operateReplace bulb
Repair as necessary
Headlights do not light
Check switch
Repair as necessaryCheck rheostat
Repair as necessary Only one light comes
ON
Turn signal does not
flash on one side
Turn signals do not
operateBE±3
BE±3
BE±18
BE±15
BE±25
Adjust or replace switch
Stop light switch faultyBE±3
BE±18
BE±15
BE±25
Stop lights do not light
Stop lights stay on
BE±3
BE±19
BE±19BE±3
BE±19
BE±15
Possible cause
BE±15
BE±25
BE±3
BE±89
RemedyProblem
BE±15BE±23 BE±89BE±25
BE±25Page
± BODY ELECTRICAL SYSTEMLightingBE±14

Turn Signal Flasher
INSPECTION OF FLASHER
INSPECT FLASHER OPERATION
(a) Connect the positive (+) lead from the battery to
terminal 3 and the negative (±) lead to terminal 2.
(b) Connect the two turn signal light bulbs parallel to each
other to terminals 1 and 2, check that the bulbs turn
on and off.
HINT: The turn signal lights should flash 60 to 120 times per
minute.
If one of the front or rear turn signal lights has an open cir±
cuit, the number of flashes will be more than 140 per mi
ute.
If operation is not as specified, replace the flashes. 2. INSPECT RELAY OPERATION
(a) Apply battery voltage to terminals 1 and 3.
(b) Check that there is continuity between terminals 2
and 4.
(c) Check that there is no continuity between terminals
3 and 4.
If operation is not as specified, replace the relay.
Hazard Warning Switch
INSPECTION OF SWITCH
INSPECT SWITCH CONTINUITY
Inspect the switch continuity between terminals.
If continuity is not as specified, replace the switch or
bulb.
Switch position
OFF (Free)
ON (Lock) Terminal0)c
o
N t
o(71
± BODY ELECTRICAL SYSTEMLightingBE±19

Taillight Failure Sensor
INSPECTION OF SENSOR
1. INSPECT WARNING LIGHT OPERATION
(a) Disconnect the connector from the failure sensor and
ground the terminal 3 on the wire harness side.
(b) Remove the CHARGE fuse and turn the ignition
switch ON, check that the bulb lights.
If bulb does not light, inspect the bulb.
2. INSPECT SENSOR CIRCUIT
Disconnect the failure sensor connector and inspect the
connector on the wire harness side as shown in the chart.
If circuit is as specified, replace the relay.
Stop light switch ON (Brake pedal depressed)Stop light switch OFF (Brake pedal released)
Turn light control switch TAIL or HEAD Turn ignition switch to OFF or ACC Turn ignition switch to OFF or ACC
Turn light control switch OFF Turn ignition switch ON
Remove CHARGE fuse
Turn ignition
switch ON
Install CHARGE fuse
Tester
connectionSpecified value
Battery voltage
Battery voltage
Battery voltageBattery voltage
No voltage Continuity
No voltageContinuityNo vottage No voltage Continuity
ContinuityNo voltage
Continuity ContinuityConditionCheck for
Voltage Voltage
VoltageAlways
AlwaysAlways
± BODY ELECTRICAL SYSTEMLightingBE±20