1995 TOYOTA SUPRA bulb

SEAT BELT WARNING INSPECTION
1. INSPECT INTEGRATION RELAY OPERATION
(a) Connect the positive (+) lead from the battery to terminals 1
and 7.
(b) Connect the positive (+) lead from the battery to terminal 9
through a 3.4W test bulb.
(c) Check that the test bulb lights up and buzzer sounds for 4±8
seconds when the negative (±) lead from the battery is
connected to terminal 10.
(d) Check that the buzzer sounding in (c) stops when the
negative (±) lead from the battery is connected to terminal 8.
If operation is not as specified, replace the integration relay.
2. INSPECT RELAY CIRCUIT
Remove the relay from the junction block No.1 and inspect
the connectors on the junction block side.
 
 Tester connection to
terminal number 
 Condition
 
 Specified condition
 4±Ground Driver's door open Continuity 
 4±Ground
 
 Driver's door close
 
 No continuity
 5±Ground Ignition key Set Continuity
 5±Ground Ignition key remove No continuity
 8±Ground Driver's seat belt fasten Continuity 
 8±Ground
 
 Driver's seat belt unfasten
 
 No continuity
 10±Ground Constant Continuity
 1±Ground Constant Battery positive voltage
 9±Ground Ignition switch position ON Battery positive voltage 
 9±Ground
 
 Ignition switch position LOCK or ACC
 
 No voltage
If circuit is not as specified, try replacing the relay with a new
one.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±55

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 re-
place the part when it is found to be faulty.
 
 Trouble
 
 Parts name (See page)
 
 
Seat heaters do not operate
(Driver's and Passenger's) 
 
1. SEAT HTR Fuse (BE±6)
2. Wire Harness
 
 
 
Driver's seat heater does not operate
 
 
 
1. Seat Heater Switch (Driver's) (BE±58)
2. Seat Heater (BE±59)
3. Wire Harness
 
 
 
Passenger 's seat heater does not operate
 
 
 
1. Seat Heater Switch (Passenger's) (BE±58)
2. Seat Heater (BE±59)
3. Wire Harness
 Seat heater temperature is too hot 1. Seat Heater (BE±59)
SEAT HEATER SWITCH INSPECTION
1. INSPECT SWITCH CONTINUITY
 
 Condition
 
 Tester connection to
terminal number 
 Specified condition
 Switch ON (LEFT) 2±4  Continuity 
 Switch ON (RIGHT)
 
 4±6
 
  Continuity
 Switch OFF ±  No continuity
 Illumination circuit 3±5  Continuity
If continuity is not as specified, replace the switch or bulb.
2. INSPECT SWITCH INDICATOR
(a) Connect the positive (+) lead from the battery to terminal 2
and 6 and the negative (±) lead to terminal 1.
(b) Push the switches, check that the indicator lights up. If
operation is not as specified, replace the switch and inspect
the circuits connected to other parts. BE±58
± BODY ELECTRICAL SYSTEMSEAT HEATER SYSTEM

Check ABS warning light.
Disconnect the connectors from solenoid relay.
Check continuity between each terminal of ABS
solenoid relay shown below.
Replace bulb or combination meter assembly.
See Combination Meter Troubleshooting on page BE±43.
(1) Apply battery positive voltage between termi-
nals (A9) 1 and (A8) 3.
(2) Check continuity between each terminal of
ABS solenoid relay shown below.
Connect the
test lead to terminal (A9)4 and the
 lead to the terminal (A9)5. Check continuity be-
tween the terminals.
Continuity
If there is no continuity, connect the  test lead to
terminal (A9)4 and the
lead to terminal (A9)5.
Recheck continuity between terminals.
Terminals (A9) 5 and (A9) 6
Terminals (A9) 2 and (A9) 5
Open
Continuity
Continuity
Open
Terminals (A9) 1 and (A8) 3
Terminals (A9) 5 and (A9) 6
Terminals (A9) 2 and (A9) 5
Continuity
(Reference value 80
)
Replace ABS control relay.
Check ABS solenoid relay.
Repair or replace and check for open in harness and connector between DLC1 and ABS solenoid
relay and body ground (See page IN±30).Repair or replace and check for open in harness and connector between DLC1 and ABS solenoid
relay and body ground (See page IN±30).
INSPECTION PROCEDURE (w/o TRAC)
Perform troubleshooting in accordance with the chart below for each trouble symptom.
 


ABS warning light does not light up
 
 Go to step [1]
 


ABS warning light remains on 
 Go to step [3]
BR±108± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

Check ABS warning light.
Disconnect the connectors from R/B No.5.
Check continuity between each terminal of ABS
solenoid relay shown below.
Replace bulb or combination meter assembly.
1. Apply battery positive voltage between ter±
minals 4 and 6.
2. Check continuity between each terminal of
ABS solenoid relay shown below.
Terminals 2 and 3
Terminals 1 and 3
Open
Continuity
Continuity
Open
Terminals 4 and 6
Terminals 2 and 3
Terminals 1 and 3
Continuity
(Reference value 80
)
Replace ABS solenoid relay.
Check ABS solenoid relay.
Repair or replace and check for open in harness and connector between DLC1 and ABS solenoid
relay and body ground (See page IN±30).
Connect the
test lead to terminal 5 and the 
lead to the terminal 3. Check continuity between
the terminals.
Continuity
If there is no continuity, connect the  test lead to
terminal 5 and the
lead to terminal 3. Recheck
continuity between terminals.
See Combination Meter Troubleshooting on page BE±43.
INSPECTION PROCEDURE (w/ TRAC)
Troubleshoot in accordance with the chart below for each trouble symptom.
 ABS warning light does not light up Go to step [1]
 ABS warning light remains on Go to step [3]
BR±110± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

To Ignition SW
IG Terminal
Fuse
Relay
SW2 SolenoidVoltmeter [A]
[B]
[C] SW1
Ohmmeter
SW
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
A±5
6
Wire Harness Repair Manual (RM1022E)
HOW TO PERFORM FOR SYSTEM INSPECTION
This inspection procedure is a simple troubleshooting which should be carried out on the vehicle during
system operation and is based on the assumption of system component trouble
Always inspect the trouble taking the following items into consideration:

Ground point fault

Open or short circuit of the wire harness

Connector or terminal connection fault

Fuse or fusible link fault
NOTICE:

This is an on±vehicle inspection during system operation.
Therefore, inspect the trouble with due regard for safety.

If connecting the battery directly, be careful not to cause a short circuit, and select the applicable
voltage.
1. Voltage Check
(a)Establish conditions in which voltage is present at the
check point.
Example:
[A] ± Ignition SW on
[B] ± Ignition SW and SW 1 on
[C] ± Ignition SW, SW 1 and Relay on (SW 2 off)
(b)Using a voltmeter, connect the negative (±) lead to a
good ground point or negative (±) battery terminal
and the positive (+) lead to the connector or
component terminal. This check can be done with a
test bulb instead of a voltmeter.
2. Continuity and Resistance Check
(a)Disconnect the battery terminal or wire so there is no
voltage between the check points.
(b)Contact the two leads of an ohmmeter to each of the
check points.
A

Diode Ohmmeter
Diode Ohmmeter
Digital Type Analog Type
Bulb Ohmmeter
A±6
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
7
Wire Harness Repair Manual (RM1022E)
If the circuit has diodes, reverse the two leads and check
again.
When touching the negative (±) lead to the diode positive
(+) side and the positive (+) lead to the negative (±) side,
there should be continuity. When touching the two leads in
reverse, there should be no continuity.
HINT: Specifications may vary depending on the type of
tester, so refer to the tester's instruction manual before
performing the inspection.
Check LED (Light Emitting Diode) in the same manner as
that for diodes.
HINT:

Use a tester with a power source of 3V or greater to
overcome the circuit resistance.

If a suitable tester is not available, apply battery
voltage and check that the LED lights up.
(c)Use a volt/ohmmeter with high impedance (10kW/V
minimum) for troubleshooting of the electrical circuit.
3. Bulb Check
(a)Remove the bulb.
(b)There should be continuity between the respective
terminals of the bulb together with a certain amount
of resistance.
(c)Apply the two leads of the ohmmeter to each of the
terminals.
(d)Apply battery voltage and check that the bulb light up.
A

Fuse Case Test Bulb
Short [A]
SW1
Short [B]
Relay
Light
Short [C]
SW2 SolenoidDisconnect
Disconnect DisconnectTo Ignition SW
IG Terminal
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
A±7
8
Wire Harness Repair Manual (RM1022E)
4. Finding a Short Circuit
(a)Remove the blown fuse and eliminate all loads from
the fuse.
(b)Connect a test bulb in place of the fuse.
(c)Establish conditions in which the test bulb comes on.
Example:
[A] ± Ignition SW on
[B] ± Ignition SW and SW 1 on
[C] ± Ignition SW, SW 1 and Relay on (Connect the Relay)
and SW 2 off (or disconnect SW 2)
(d)Disconnect and reconnect the connectors while
watching the test bulb. The short lies between the
connector where the test bulb stays lit and the
connector where the bulb goes out.
(e)Find the exact location of the short by lightly shaking
the problem wire along the body.
CAUTION:
(a)Do not open the cover or the case of the ECU
unless absolutely necessary. (If the IC terminals
are touched, the IC may be destroyed by static
electricity.)
(b)When replacing the internal mechanism (ECU
part) of the digital meter, be careful that no part of
your body or clothing comes in contact with the
terminals of leads from the IC, etc. of the
replacement part (spare part).
A