TOYOTA SUPRA 1995 Service Repair Manual

SEAT HEATER INSPECTION
1. INSPECT SEAT CUSHION CONTINUITY
(a) Heat the thermostat with a light.
(b) Inspect the seat heater continuity between terminals.
 
 
 
Tester connection to
terminal number
 
 
 
Condition
 
 
 
Specified condition
 A1±A2 Constant Continuity
 A1±B2 Constant Continuity
 A2±B2 Constant Continuity 
 A3±A4
 
 Seat heater temperature
below 25°C(77°F)
 
 Continuity
 
 
 
A4±B1
 
 
 
Seat heater temperature
below 25°C(77°F)
 
 
 
Continuity
 
 
A3±A4 
 
Seat heater temperature
above 45°C(113°F) 
 
No Continuity
 
 A4±B1 
 
Seat heater temperature
above 45°C(113°F) 
 No Continuity
If continuity is not as specified, replace the seat cushion pad.
2. INSPECT SEAT BACK CONTINUITY
Inspect the seat heater continuity between terminals, as
shown.
 
 

Tester connection to
terminal number
 
 

Condition
 
 

Specified condition
 
 1±3
 
 Constant
 
 Continuity
 2±4 Constant Continuity
If continuity is not as specified, replace the seat back pad.
± BODY ELECTRICAL SYSTEMSEAT HEATER SYSTEMBE±59

SEAT HEATER RELAY INSPECTION
INSPECT RELAY CONTINUITY
 
 Condition
 
 
Tester connection to
terminal number 
 Specified condition
 Constant 1±3 Continuity 
 Apply B+ between
Terminals 1 and 3.
 
 2±4
 
 Continuity
If continuity is not as specified, replace the relay. BE±60
± BODY ELECTRICAL SYSTEMSEAT HEATER SYSTEM

ELECTRIC TENSION REDUCER
SYSTEM
PARTS LOCATION
± BODY ELECTRICAL SYSTEMELECTRIC TENSION REDUCER SYSTEMBE±61

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.
 Trouble  Parts name (See page)
 
 
Tension Reducer does not operate.
(Driver's and Passenger's) 
 
1. ECU±IG fuse (BE±6)
2. Wire Harness
 
 
 
Tension Reducer does not operate.
(Only one side)
 
 
 
1. Buckle Switch (BE±56)
2. Tension Reducer Solenoid (BE±62)
3. Wire Harness
TENSION REDUCER SOLENOID
INSPECTION
INSPECT SOLENOID OPERATION
(a) Connect the positive (+) lead from the battery to terminal 1,
and negative (±) lead to terminal 2.
(b) Pull the belt upward and check that the belt is slowly retracted
when released.
(c) Disconnect the lead from the battery.
(d) Pull the belt upward and check that the belt is retracted more
quickly when released than in (b).
HINT: Do not tilt the retractor.
If the operation is not as specified, replace the front seat outer
belt assembly.
BUCKLE SWITCH INSPECTION
See page BE±56 BE±62
± BODY ELECTRICAL SYSTEMELECTRIC TENSION REDUCER SYSTEM

DEFOGGER SYSTEM
PARTS LOCATION
± BODY ELECTRICAL SYSTEMDEFOGGER SYSTEMBE±63

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.
 Trouble Parts name (See page)
 
 
 
 
 
 
All defogger systems do not operate
 
 
 
 
 
 
1. GAUGE Fuse (BE±6)
2. DEFOG Fuse (BE±6)
3. Defogger Relay (BE±65)
4. Defogger Switch (BE±64)
5. A/C Amplifier (AC Section)
6. Wire Harness
 
 
Rear window defogger does not operate 
 
1. Defogger Wires (BE±65)
2. Wire Harness
 
 
 
Mirror defogger does not operate
 
 
 
1. MIR±HTR Fuse (BE±6)
2. Mirror Defogger (BE±66)
3. Wire Harness
DEFOGGER SWITCH INSPECTION
INSPECT SWITCH OPERATION
(a) Connect the positive (+) lead from the voltmeter to terminal
7 of connector B and the negative (±) lead from voltmeter to
terminal 10 of connector B.
(b) When the switch is off, the voltage should be approx. 12 V.
(c) When the switch is on, check that the indicator light lights up
and that the voltage is less than 1 V.
(d) After 15 minutes, check that the switch is off and the voltage
is approx. 12 V.
A/C AMPLIFIER INSPECTION
See A/C section BE±64
± BODY ELECTRICAL SYSTEMDEFOGGER SYSTEM

DEFOGGER 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.
DEFOGGER WIRE INSPECTION
NOTICE:
wWhen cleaning the glass, use a soft, dry cloth, and
wipe the glass in the direction of the wire. Take care
not to damage the wires.
wDo not use detergents or glass cleaners with
abrasive ingredients.
w When measuring voltage, wind a piece of tin foil
around the top of the negative probe and press the
foil against the wire with your finger, as shown.
(a) Turn the ignition switch ON.
(b) Turn the defogger switch ON.
(c) Inspect the voltage at the center of each heat wire, as shown.
 Voltage Criteria
 Approx. 5V Okay (No break in wire)
 Approx. 10V or 0V Broken wire
HINT: If there is approximately 10 V, the wire is broken be-
tween the center of the wire and the positive (+) end. If there
is no voltage, the wire is broken between the center of the
wire and ground.
(d) Place the voltmeter positive (+) lead against the defogger
positive (+) terminal.
(e) Place the voltmeter negative (±) lead with the foil strip against
the heat wire at the positive (+) terminal end and slide it
toward the negative (±) terminal end.
(f) The point where the voltmeter deflects from zero to several
V is the place where the heat wire is broken.
HINT: If the heat wire is not broken, the voltmeter indicates
O V at the positive (+) end of the heat wire but gradually in-
creases to about 12 V as the meter probe is moved to the oth-
er end.
± BODY ELECTRICAL SYSTEMDEFOGGER SYSTEMBE±65

DEFOGGER WIRE REPAIR
(a) Clean the broken wire tips with a grease, wax and silicone
remover.
(b) Place the masking tape along both sides of the wire to be
repaired.
(c) Thoroughly mix the repair agent (DuPont paste No. 4817).
(d) Using a fine tip brush, apply a small amount to the wire.
(e) After a few minutes, remove the masking tape.
(f) Allow the repair to stand at least 24 hours.
MIRROR DEFOGGER INSPECTION
1. INSPECT MIRROR DEFOGGER OPERATION
(a) Connect the positive (+) lead from the battery to terminal 2
and the negative (±) lead to terminal 1.
(b) Check that the mirror becomes warm.
HINT: It will take a short time for the mirror to become warm.
If the mirror does not become warm, replace the mirror as-
sembly.
2. INSPECT MIRROR DEFOGGER CIRCUIT
Disconnect the connector from the outside mirror and inspect
the connector on the wire harness side, as shown.
 
 
Tester connection to
terminal number 
 Condition
 
 Specified condition
 1±Ground Constant Continuity 
 2±Ground
 
 Ignition switch ON (Defogger switch OFF)
 
 No voltage
 2±Ground Ignition switch ON (Defogger switch ON) Battery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts. BE±66
± BODY ELECTRICAL SYSTEMDEFOGGER SYSTEM

POWER WINDOW CONTROL
SYSTEM
PARTS LOCATION
± BODY ELECTRICAL SYSTEMPOWER WINDOW CONTROL SYSTEMBE±67

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.
 Trouble Parts name (See page)
 
 
 
 
 
 
*1 Power window does not operate.
 
 
 
 
 
 
1. ALT Fuse (BE±5)
2. POWER Fuse (BE±5)
3. AM 1 Fuse (BE±5)
4. DOOR Fuse (BE±6)
5. Ignition Switch (BE±8)
6. Power Window Master Switch (BE±69)
7. Wire Harness
 
 
 
 
 
*2 Power Window does not operate.
 
 
 
 
 
1. GAUGE Fuse (BE±6)
2. Power Main Relay (BE±73)
3. Ignition Switch (BE±8)
4. Power Window Master Switch (BE±69)
5. Wire Harness
 ºOne Touch Power Window Systemº does not operate. 1. Power Window Master Switch (BE±69) 
 
 
 
Only one window glass does not move.
 
 
 
 
1. Power Window Master Switch (BE±69)
2. Power Window Switch (BE±71)
3. Power Window Motor (BE±71)
4. Wire Harness
 ºWindow Lock Systemº does not operate. 1. Power Window Master Switch (BE±69) 
 Illumination does not light up.
 
 1. Power Window Master Switch (BE±69)
*1 Power door lock does not operate.
*
2 Power door lock is normal. BE±68
± BODY ELECTRICAL SYSTEMPOWER WINDOW CONTROL SYSTEM