ignition TOYOTA CAMRY V20 1986 Service Information

Does warning light go off when both the com-
puter connector and check connector are
.. disconnected? (Ignition switch on)Is there 10 ± 16 V between terminal IG on
computer wire harness side connector and
body ground? (ignition switch on)
Short circuit in wire harness between
computer terminal W and actuator ter-
minal W. Is connector of computer properly connected?
And are all terminals in the connector?Continued from page
BR±71.
Faulty power circuit.
Faulty computer.Faulty connector.
NO
(Come on)
YES
(Goes off¿ YES
YES
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±72

HINT: If the diode is short±circuited, a mal-
function at computer terminal W will occur.
When inspecting the terminal, connect the
computer connector, and disconnect actua-
tor connectors. Then turn the ignition switch
on, and check that the warning fight goes
on. If it does, the computer terminal is OK. Disconnect connectors from computer and ac-
tuator, and ground terminal W of computer wire
harness side connector.
(Ignition switch on)Disconnect check connector from actuator,
and ground the terminal W of the wire har-
ness side connector.
(Ignition switch on)
With ignition switch off, disconnect actuator
connectors, and check continuity between ter-
minal W and AST on actuator side.ºANTILOCKº warning light does not come on for 3 seconds after ignition switch on.
Bulb burned out or open circuit in wire
harness between warning light and ac-
tuator terminal W.
Open circuit in wire harness between
computer terminal W and warning light.
Reverse tester leads and check again.
Is there one way continuity between terminals?Short circuit in actuator inside diode. Does warning light come on?Does warning light come on?
Faulty computer.YES
YES
YES
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±73

wCheck connector is disconnected.
wOpen circuit in wire harness between computer terminal T and actuator terminal T.
wActuator terminal GND is improperly connected or open circuit in wire harness between actuator
terminal GND and body ground.
wConnect circuit in wire harness between computer terminal Ts and Ts connector. (For 4WD)
wBrakes pull.
wBraking inefficient.
wA.B.S. operates at ordinary braking.
wA.B.S. operates just before stopping at ordinary braking.
wBrake pedal pulsates abnormally while A.B.S. working.
Disconnect connector from computer, inspect
continuity between each speed sensor termi-
nals on wire harness side.
(See page BR±103) Are each speed sensors installed in place?
And are each installation bolts tightened se-
curely?Does warning light show the diagnostic
normal code? (Ignition switch on)ºANTILOCKº warning light comes on and off.
Disconnect check connector.
(See page BR±68)
See diagnostic code.
(See page BR±69)
Speed sensor installation faulty.
Continued on page BR±75 YES
YES
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±74

Is there battery voltage between comput-
er terminal STP and body ground when
depressing brake pedal?Does warning light show the diagnostic
normal code? (ignition switch on)
Open circuit in stop light switch and/or
wire harness. Disconnect check connector.
(See page BR±68) Anti±lock brake system works inefficiently.
See diagnostic code.
(See page BR±69)
Inspect actuator.
(See page BR±84)YESYES
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±76

Speed Sensor Diagnosis System
PRECAUTION
While checking the speed sensor diagnosis system,
A.B.S. does not work and brake system works as normal
brake system.
INSPECTION OF DIAGNOSIS SYSTEM
1. INSPECT BATTERY VOLTAGE
Inspect that the battery voltage is about 12 V.
2. CHECK THAT WARNING LIGHT TURNS ON
(a) Turn the ignition switch on.
(b) Check that the ºANTILOCKº warning light turns on for
3 seconds.
If not, inspect and repair or replace the fuse, bulb and wire
harness.
(c) Check that the ºANTILOCKº warning light turns off.
(d) Turn the ignition switch off.
3. PERFORM FOLLOWING STEPS
(2WD)
(a) Disconnect the check connector from the actuator.
(b) Pull the parking brake lever up, and start the engine.
(d) Check that the warning light blinks about 4 times ev-
ery 1 second as shown. (c) Depress the brake pedal 4 to 6 times within 2
seconds.
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±77

5. INSPECT SENSOR SIGNAL CHANGE
Drive the vehicle straight ahead at about 45 ± 55 krn/h
(28.0 ± 34.2 mph), and check that the warning light turns
on after a 1 second pause.
If the warning light turns on without blinking when the ve-
hicle speed is not within the specified speed range above,
stop the vehicle and read the diagnostic code, and repair
the malfunctioning .parts.
(See step 6 on this page)
HINT: If the warning light turns on while the vehicle speed
is within specified speed range above, the check is com-
pleted. And when the vehicle speed is not within specified
speed range, the warning light will blink again. In this con-
dition, sensor rotors are OK.
NOTICE: While the warning light is off, do not give any
shocks to vehicle such as acceleration, deceleration, brak-
ing, shift change, steering or shocks from the road condi-
tion.
HINT: The first number of blinks will equal the first digit
of a two digit diagnostic code. After a 1.5 second pause,
the 2nd number of blinks will equal the 2nd number of a
two digit code. If there are two or more codes, there will
be a 2.5 second pause between each code, and then
indication will begin again after a 4.0 second pause,
continuing in order from the smaller value up to the larg-
er one. 6. READ DIAGNOSTIC CODE
Stop the vehicle and disconnect the check connector, and
warning light will begin to blink. Read the number of
blinks.
(See DIAGNOSTIC CODE on page BR±81)
7. REPAIR MALFUNCTIONING PARTS
Repair or replace the malfunctioning parts.
HINT: When repairing or replacing parts, turn the ignition
switch OFF.
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±79

(For 4WD)
(c) Remove the short pin or wire from the Ts connector
and install the rubber cap to it.
(d) Turn the ignition switch off. 8. PERFORM FOLLOWING STEPS
(a) (2WD)
Turn the ignition switch on.
(4WD)
Turn the ignition switch off.
(b) Connect the check connector.
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±80

Deceleration Sensor Operation
Diagnosis System (For 4WD)
PRECAUTION
While checking the deceleration sensor diagnosis
system, A.B.S. does not work and brake system works as
normal brake system.
INSPECTION OF DIAGNOSIS SYSTEM
1. INSPECT BATTERY VOLTAGE
Inspect that the battery voltage is about 12 V.
2. CHECK THAT WARNING LIGHT TURNS ON
(a) Turn the ignition switch on.
(b) Check that the ºANTILOCKº warning light turns on for
3 seconds.
If not, inspect and repair or replace the fuse, bulb and wire
harness.
(e) Check that the ºANTILOCKº warning light turns off.
(d) Turn the ignition switch off.
3. PERFORM FOLLOWING STEPS
(a) Remove the rubber cap from the Ts connector lo-
cated in front of the actuator.
(b) Connect the terminals of Ts connector.
(c) Pull the parking brake lever up and depress the brake
pedal, and start the engine.
4. INSPECT SENSOR DETECTION POINT
(a) Jack up the rear side of the vehicle slowly as shown.
HINT: When measuring the height, measure at the center
of the rear bumper lower edge.
(b) Check that the warning light does not turn on.
(c) Jack down the vehicle and check that the warning
light blinking. (d) Check that the warning light blinks about 1 time every
1 second as shown.
If the warning light does not blink, inspect the parking brake
switch, stop light switch, Ts connector, deceleration sensor
installation and computer.
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±82

Anti±lock Brake System Circuit
INSPECTION OF SYSTEM CIRCUIT
1. INSPECT SYSTEM CIRCUIT WITH CONNECTOR
CONNECTED
(a) Remove the A.B.S. computer.
(b) Using a voltmeter with high impedance (10 K

/V
minimum), measure the voltage at each terminal and
body ground.
If the circuit is not as specified, check and repair or re-
place the trouble part shown in the table above.
Ignition switch on and ºANTI LOCKº warning light goes on
Ignition switch on and ºANTI LOCKº warning light goes on
Ignition switch on and ºANTI LOCKº warning light goes onIgnition switch on and ºANTI LOCKº warning light goes on Ignition switch on and ºANTI LOCKº warning light goes on
Ignition switch on and ºANTI LOCKº warning light goes on
Check connector connectedºANTI LOCKº
warning light bulb
Check connector disconnected
Check connector,
computer Actuator, control
relays
AST ± Body groundSRR ± Body groundSRl ± Body ground SFR ± Body groundSFL ± Body ground
W ± Body ground
T ± Body ground Tester Connection
Ignition switch on Ignition switch on
Ignition switch on Ignition switch on
Ignition switch on Ignition switch on
Battery voltage Battery voltage
Battery voltage Battery voitage Battery voltage
Battery voltage Battery voltageTrouble Part
About 0 V
About 0 V About 0 V About 0 V
About 0 V
About 0 V
About 0 V ConditionVoltage
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±102

2. INSPECT SYSTEM CIRCUIT WITH CONNECTOR
DISCONNECTED
(a) Disconnect the connectors from the computer, in-
spect at the wire harness side connector.
If the circuit is not as specified, check and repair or re-
place the trouble part shown in the table above.
(b) Connect the connectors, and install the comput-
er cover.
Ignition switch off and brake pedal depressed
Engine running and PKB lever returned Ignition switch off and brake pedal returned
Ignition switch on and PKB lever pulled
Parking broke switch,
level warning switchStop light switch,
stop light Voltage or
Resistance Value
Check connector,
wiring harness
Front RH speed
sensor
FrontrH speed
sensor Ts connector,
wiring harness
Rear RH speed
sensor
Rear RH speed
sensor
Rear LH speed
sensorRear LH speed
sensor Ts connector shorted
Ignition switch offIgnition switch off
Ignition switch off
Ignition switch off Ignition switch off Tester Connection
Ignition switch offIgnition switch off
Ignition switch off
Ignition switch off Ignition switch off Ignition switch off
Ignition switch offIgnition switch off
Ignition switch onBattery voltage
No continuity
Battery voltage
0.85 ± 1.30 k fl
0.85± 1.30k
Battery voltage
Wiring harnessWiring harness
Wiring harness Battery voltage
0.85 ± 1.50 k
0.85 ± 1.50 k

No continuityNo continuity
No continuityNo continuityNo continuityTrouble Part
65±100

ECU±IG fuse Chrak Item
50±80

About 6
ContinuityResistance
Resistance
About 5
ResistanceAbout 6 0
Resistance
ResistanceAbout 6

ResistanceContinuity Resistance
Resistance
ResistanceContinuity
ResistanceAbout 6

ResistanceContinuity
Continuity
Continuity
ContinuityContinuity Continuity
Continuity Continuity
About 0 v
Continuity Continuity
Continuity
Continuity
FOG fuse Condition
ActuatorActuator
Actuator Voltage
VoltageVortege
Actuator Voltage
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±103