TOYOTA SUPRA 1995 Service Repair Manual

KEY UNLOCK WARNING INSPECTION
1. INSPECT INTEGRATION RELAY OPERATION
(a) Connect the positive (+) lead from the battery to terminal 1,
the negative (±) lead to terminals 5 and 10.
(b) Check that the buzzer sounds when the negative (±) lead
from the battery is connected to terminal 6.
If operation is not as specified, replace the relay.
2. INSPECT RELAY CIRCUIT
See page BE±18
± BODY ELECTRICAL SYSTEMIGNITION SWITCHBE±9

HEADLIGHT AND TAILLIGHT
SYSTEM
PARTS LOCATION
BE±10± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEM

TROUBLESHOOTING
The table below will be useful for you in troubleshooting these electrical problems. The most likely causes
of the malfunction are shown in the order of their probability. Inspect each part in the order shown, and
replace the part when it is found to be faulty.
USA:
 Trouble Parts name (See page)
 
 
 
 
 
 
 
Headlight does not light
(Taillight is normal)
 
 
 
 
 
 
 
1. FL MAIN
2. HEAD Fuse (LH, RH) (BE±5)
3. Headlight Control Relay (BE±16)
4. Headlight Dimmer Switch (BE±15)
5. Light Control Switch (BE±15)
6. Integration Relay (BE±17)
7. Wire Harness
8. Headlight Bulb
 
 
 
 
 
Headlight does not light
(Taillight does not light up)
 
 
 
 
 
1. FL MAIN
2. Light Control Switch (BE±15)
3. Integration Relay (BE±17)
4. Wire Harness
5. Headlight Bulb
 
 
 
Only one side light does not light
 
 
 
1. HEAD Fuse (LH, RH) (BE±5)
2. Headlight Bulb
3. Wire Harness
 
 
ºLo±Beamº does not light 
 
1. Headlight Dimmer Switch (BE±15)
2. Wire Harness
 
 
ºHi±Beamº does not light 
 
1. Headlight Dimmer Switch (BE±15)
2. Wire Harness
 

ºFlashº does not light 

1. Headlight Dimmer Switch (BE±15)
2. Wire Harness
CANADA:
 
 Trouble
 
 Parts name (See page)
 
 
 
 
 
 
 
 
Headlight does not light
(Taillight is normal)
 
 
 
 
 
 
 
 
1. FL MAIN
2. Headlight Control Relay
3. Daytime Running Light Relay (BE±18)
4. Daytime Running Light No.2 and No.3 Relay (BE±19)
5. Headlight Dimmer Switch (BE±15)
6. Light Control Switch (BE±15)
7. Integration Relay (BE±17)
8. Wire Harness
9. Headlight Bulb
 
 
 
 
 
Headlight does not light
(Taillight does not light up)
 
 
 
 
 
1. FL MAIN
2. Light Control Switch (BE±15)
3. Daytime Running Light Relay (BE±18)
4. Daytime Running Light No.2 and No.3 Relay (BE±19)
5. Integration Relay (BE±17)
6. Wire Harness
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEMBE±11

 Trouble Parts name (See page)
 
 Only one side light does not light 
 
1. Headlight Bulb
2. Wire Harness
 
 ºLo±Beamº does not light (ALL) 
 
1. Headlight Control Relay (BE±16)
2. Wire Harness
 
 
 
ºLo±Beamº does not light (ONE SIDE)
 
 
 
1. HEAD LH±LWR Fuse (BE±5)
2. HEAD RH±LWR Fuse (BE±5)
3. Headlight Bulb
4. Wire Harness
 
 
 
 
ºHi±Beamº does not light (ALL)
 
 
 
 
1. Headlight Dimmer Switch (BE±15)
2. Daytime Running Light Relay (BE±18)
3. Daytime Running Light No.2 and No.3 Relay (BE±19)
4. Wire Harness
 
 
 
 
ºHi±Beamº does not light (ONE SIDE)
 
 
 
 
1. HEAD LH±UPR Fuse (BE±5)
2. HEAD RH±UPR Fuse (BE±5)
3. Headlight Bulb
4. Wire Harness
 
 
 
 
ºFlashº does not light
 
 
 
 
1. Headlight Dimmer Switch (BE±15)
2. Daytime Running Light Relay (BE±18)
3. Daytime Running Light No.2 and No.3 Relay (BE±19)
4. Wire Harness
 
 
 
ºAuto Turn±off Systemº dose not operate
 
 
 
1. Integration Relay (BE±17)
2. GAUGE Fuse (BE±6)
3. Wire Harness
4. Door Courtesy Switch (driver's) (BE±28)
 
 
 
 
 
Headlight does not light with light control SW in HEAD.
 
 
 
 
 
1. Integration Relay (BE±17)
2. Light Control Switch (BE±15)
3. Daytime Running Light Relay (BE±18)
4. Daytime Running Light No.2 and No.3 Relay (BE±19)
5. Wire Harness
 
 Headlight does not go out with light control SW in OFF 
 
1. Headlight Control Relay (BE±16)
2. Wire Harness
 
 
 
 
Taillight does not light with light control SW in TAIL
 
 
 
 
1. Taillight Control Relay (BE±16)
2. Integration Relay (BE±17)
3. Light Control Switch (BE±15)
4. Wire Harness
 
 
 
Taillight does not go out with light control SW in OFFª
 
 
 
1. Taillight Control Relay (BE±16)
2. Integration Relay (BE±17)
3. Light Control Switch (BE±15)
4. Wire Harness
 
 
 
 
 
 
Headlight and Taillight do not light with engine running and
light control SW in OFF
 
 
 
 
 
 
1. GAUGE Fuse (BE±6)
2. Daytime Running Light Relay (BE±18)
3. Daytime Running Light No.2 and No.3 Relay (BE±19)
4. Wire Harness
5. Generator L Terminal
6. Parking Brake Switch (BE±52)
BE±12± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEM

HEADLIGHT AIM ADJUSTMENT
Adjusting headlight aim only
1. INSPECT HEADLIGHT AIM
Do the following before inspection.
wMake sure the body around the headlight is not
deformed.
wPark the vehicle on a level spot.
wThe driver gets into the driver's seat and puts the vehicle
in a state ready for driving (with a full tank).
wBounce the vehicle several times.
2. ADJUST HEADLIGHT VERTICAL ALIGNMENT
If the bubble is outside the acceptable range of the beam
angle gauge, adjust it using adjusting screw A.
3. ADJUST HEADLIGHT HORIZONTAL ALIGNMENT
If the º0º moves away from the mark beyond the acceptable
range, adjust the º0º back to the mark using adjusting screw
B.
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEMBE±13

Replacing headlight
1. REPLACE HEADLIGHT
2. INSPECT HEADLIGHT AIM
Do the following before inspection.
wMake sure the body around the headlight is not
deformed.
wPark the vehicle on a level spot.
wThe driver gets into the driver's seat and puts the vehicle
in a state ready for driving (with a full tank).
wBounce the vehicle several times.
3. ADJUST HEADLIGHT IN VERTICAL ALIGNMENT
(a) Using adjusting screw A, adjust the headlight aim to within
the specifications.
(b) Make sure the gauge bubble is within the acceptable range.
HINT: If the gauge bubble is outside the acceptable range,
check that the vehicle is parked on a level spot. Readjust the
headlight aim after parking the vehicle on a level spot.
4. ADJUST HEADLIGHT IN HORIZONTAL ALIGNMENT
(a) Using adjusting screw B, adjust the headlight aim to within
the specifications.
(b) Using adjusting nut C, adjust the º0º back to the mark.
HINT: For adjustment, pull nut C to the rear vehicle to free it.
After adjustment, check that the nut C is locked in.
COMBINATION SWITCH REMOVAL AND
INSTALLATION
See SR±Section BE±14
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEM

COMBINATION SWITCH DISASSEMBLY
AND ASSEMBLY
COMBINATION SWITCH INSPECTION
1. INSPECT LIGHT CONTROL SWITCH CONTINUITY 
 Switch position
 
 Tester connection to
terminal number
 
 Specified condition
 
 OFF
 
 ±
 
  No continuity
 TAIL A2±A11  Continuity
 HEAD A2±A11±A13  Continuity
If continuity is not as specified, replace the switch.
2. INSPECT DIMMER SWITCH CONTINUITY
 
 Switch position
 
 
Tester connection to
terminal number 
 Specified condition
 Flash A9±A12±A14  Continuity
 Low beam A3±A9  Continuity High beam A9±A12  Continuity
If continuity is not as specified, replace the switch.
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEMBE±15

HEADLIGHT CONTROL RELAY
INSPECTION
INSPECT RELAY CONTINUITY 
 Condition
 
 Tester connection to
terminal number 
 Specified condition
 Constant 3±4 Continuity 
 Apply B+ between
Terminal 3 and 4. 
 1±2
 
 Continuity
If continuity is not as specified, replace the relay.
TAILLIGHT RELAY INSPECTION
INSPECT RELAY CONTINUITY
 
 Condition
 
 Tester connection to
terminal number 
 Specified condition
 Constant 1±2 Continuity 
 Apply B+ between
Terminals 1 and 2. 
 3±5
 
 Continuity
If continuity is not as specified, replace the relay. BE±16
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEM

INTEGRATION RELAY INSPECTION
INSPECT RELAY CIRCUIT
Light Auto Turn Off System
Remove the relay from junction block and inspect the con-
nectors on the wire harness and junction block side, as
shown in the chart.
 
 
Tester connection to
terminal number 
 Condition 
 Specified condition
 A6±Ground  Driver's door courtesy switch OFF No continuity
 A6±Ground Driver's door courtesy switch ON Continuity
 A10±Ground Constant Continuity
 B1±Ground Light control switch position OFF or TAIL No continuity
 B1±Ground Light control switch position HEAD Continuity
 B4±Ground Light control switch position OFF No continuity B4±Ground Light control switch position TAIL or HEAD Continuity A1±Ground Constant Battery positive voltage 
 A7±Ground
 
 Ignition switch position LOCK or ACC
 
 No voltage
 A7±Ground Ignition switch position ON Battery positive voltage
 B2±Ground Constant Battery positive voltage
 B3±Ground Constant Battery positive voltage
If the circuit is as specified, try replacing the relay with a new
one.
If the circuit is not as specified, inspect the circuits connected
to other parts.
DOOR COURTESY SWITCH INSPECTION
See page BE±28
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEMBE±17

DAYTIME RUNNING LIGHT MAIN RELAY
INSPECTION
INSPECT RELAY CIRCUIT
Disconnect the connector from relay and inspect the connec-
tor on wire harness side, as shown.
 
 Tester connection to
terminal number 
 Condition
 
 Specified condition
 
 5±Ground
 
 Headlight dimmer switch position Low
beam or high beam 
  No continuity
 5±Ground  Headlight dimmer switch position Flash Continuity 8±Ground Parking brake switch position OFF No continuity 8±Ground Parking brake switch position ON Continuity 
16±Ground
 
Headlight dimmer switch position Low beam
 
No continuity
 16±Ground Headlight dimmer switch position Flash or
High beam Continuity
 
 13±Ground
 
 Constant
 
 Continuity
 18±Ground Constant Continuity
 2±Ground Ignition switch position LOCK or ACC No voltage
 2±Ground Ignition switch position ON Battery positive voltage
 11±Ground Engine Stop No voltage
 11±Ground Engine Running Battery positive voltage
 15±Ground  
15±Ground
17 GroundConstantBattery positive voltage 17±Ground Constant Battery ositive voltage
If the circuit is as specified, trying replacing the relay with a
new one. If the circuit is not as specified, inspect the circuit
connected to other parts.
PARKING BRAKE SWITCH INSPECTION
See page BE±52 BE±18
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEM