1995 TOYOTA SUPRA warning light

INDICATOR LIGHTS
TroubleParts name (See page) 
 
 SRS Indicator Light does not light up
 
 
 
1. Bulb
2. Wire Harness
3. Center Air Bag Sensor (RS Section)
 
 
 
ABS Indicator Light does not light up
 
 
 
1. Bulb
2. Wire Harness
3. Traction ECU (BR Section)
 
 
 
Malfunction Indicator Light does not light up
 
 
 
1. Bulb
2. ECM (EG Section)
3. Wire Harness
 
 
 
TRAC OFF Indicator Light does not light up
 
 
 
1. Bulb
2. Traction Solenoid Relay (BR Section)
3. Traction ECU (BR Section)
4. Wire Harness
 
 
 
Security Indicator Light does not light up
 
 
 
1. Light Emitting Diode
2. Theft Deterrent and Door Lock ECU (BE±123)
3. Wire Harness
 
 
 
 
A/T Shift Position Indicator Light does not light up
 
 
 
 
1. Bulb
2. Park/Neutral Position Switch (AT1 Section)
3. Light Control Rheostat (BE±54)
4. Meter Circuit Plate (BE±44)
5. Wire Harness
 
 
 
 
MANU Indicator Light does not light up
 
 
 
 
1. Bulb
2. ECM (EG Section)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
 
 
 
 
O/D OFF Indicator Light does not light up
 
 
 
 
1. Bulb
2. O/D Main Switch
3. ECM (EG Section)
4. Meter Circuit Plate (BE±44)
5. Wire Harness
 
 
 
 
TRAC Indicator Light does not light up
 
 
 
 
1. Bulb
2. ABS and Traction ECU
3. Meter Circuit Plate (BE±44)
4. Wire Harness
 
 
 
Turn Indicator Light does not light up
 
 
 
1. Bulb
2. Turn Signal and Hazard Warning System (BE±20)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
 
 
 
 
High Beam Indicator Light does not light up
 
 
 
 
1. Bulb
2. Headlight System (BE±10)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
 
 
 
CRUISE Indicator Light does not light up
 
 
 
1. Bulb
2. Cruise Control ECU (BE±170)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±43

2. INSECT RECEIVER GAUGE RESISTANCE
Measure the resistance between terminals.
 Between terminals Resistance (
)
 A±B Approx. 269.7
 A±C Approx. 123.5
 B±C Approx. 146.2
If resistance value is not as specified, replace the fuel receiv-
er gauge.
3. INSPECT SENDER GAUGE RESISTANCE
Measure the resistance between terminals 2 and 3 for each
float position.
 
 Float position mm (in.)
 
 Resistance (
)
 F Approx. 33.8 (1.33) Approx. 4.0
 1/2 Approx. 44.8 (1.76) Approx. 55.0
 E Approx. 141.1 (5.55) Approx. 107.0
If resistance value is not as specified, replace the sender
gauge.
FUEL LEVEL WARNING INSPECTION
1. INSPECT WARNING LIGHT
(a) Disconnect the connector from the sender gauge.
(b) Connect terminals 1 and 3 on the wire harness side
connector.
(c) Turn the ignition switch ON, check that the warning light lights
up.
If the warning light does not light up, test the bulb or inspect
wire harness.
2. INSPECT SWITCH
(a) Apply battery positive voltage between terminals 1 and 3
through a 3.4 W test bulb, check that the bulb lights up.
HINT: It will take a short time for the bulb to light up.
(b) Submerge the switch in fuel, check that the bulb goes out.
If operation is not as specified, replace the sender gauge.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±49

LOW OIL PRESSURE WARNING
INSPECTION
1. INSPECT SWITCH
(a) Check that there is continuity between terminal and ground
with the engine stopped.
(b) Check that there is no continuity between terminal and
ground with the engine running.
HINT: Oil pressure should be over 29 kPa (0.3 kgf/ cm
2, 4.3
psi)
If operation is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the warning switch and
ground terminal on the wire harness side connector.
(b) Turn the ignition switch ON, check that the warning light lights
up.
If the warning light does not light up, test the bulb or inspect
wire harness.
ENGINE OIL LEVEL WARNING
INSPECTION
1. INSPECT SWITCH
(a) Check that there is continuity between terminal with the
switch in each position.
(b) Heat the switch to above 60°C (140°F) in an oil bath.
(c) Check that there is continuity between terminals with the
switch ON (float up).
(d) Check that there is no continuity between terminals with the
switch OFF (float down).
If operation is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the switch.
(b) Ground terminal 1 on the wire harness connector.
(c) Turn the ignition switch ON. Check that the warning light
lights up approximately 40 seconds later.
If the warning light does not light up, inspect bulb or wire har-
ness.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±51

BRAKE FLUID LEVEL WARNING
INSPECTION
1. INSPECT SWITCH
(a) Remove the reservoir tank cap and strainer.
(b) Disconnect the connector.
(c) Check that there is no continuity between terminals with the
switch OFF (float up).
(d) Use syphon, etc. to take fluid out of the reservoir tank.
(e) Check that there is continuity between terminals with the
switch ON (float down).
(f) Pour the fluid back in the reservoir tank.
If operation is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the brake fluid warning
switch.
(b) Release the parking brake pedal.
(c) Connect terminals on the wire harness side of the level
warning switch connector.
(d) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or wire har-
ness.
PARKING BRAKE WARNING
INSPECTION
1. INSPECT SWITCH
(a) Check that there is continuity between terminal and switch
body with the switch ON (switch pin released).
(b) Check that there is no continuity between terminal and switch
body with the switch OFF (switch pin pushed in).
If operation is not as specified, replace the switch or inspect
ground point.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the parking brake switch and
the brake fluid warning switch.
(b) Ground terminal on the wire harness side connector.
(c) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or inspect
wire harness. BE±52
± BODY ELECTRICAL SYSTEMCOMBINATION METER

LIGHT FAILURE SENSOR INSPECTION
1. INSPECT SENSOR CIRCUIT
Disconnect the connector from the sensor 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 Constant Continuity*
 9±Ground Constant Continuity* 
 10±Ground
 
 Constant
 
 Continuity*
 11±Ground Constant Continuity
 12±Ground Constant Continuity*
 3±Ground Light control switch position OFF No Voltage 3±Ground Light control switch position TAIL or HEAD Battery positive voltage 
 4±Ground
 
 Ignition switch position LOCK or ACC
 
 No voltage
 4±Ground Ignition switch position ON Battery positive voltage
 7±Ground Stop light switch position OFF No voltage
 7±Ground Stop light switch position ON Battery positive voltage 
 8±Ground
 
 Engine condition Stop
 
 No voltage
 8±Ground Engine condition Running Battery positive voltage
*: There is resistance because this circuit is grounded
through the bulb.
If circuit is as specified, replace the sensor.
If the circuit is not as specified, inspect the circuits connected
to other parts.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the light failure sensor and
ground terminal 4 on the wire harness side connector.
(b) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or inspect
wire harness.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±53

OPEN DOOR WARNING INSPECTION
1. INSPECT DOOR COURTESY SWITCH
 
 Switch Position
 
 
Tester connection to
terminal number 
 Specified condition
 
 ON
(Switch pin released) 
 1±2
2±3 
 Continuity
 
 OFF
(Switch pin pushed in) 
 ±
 
 No continuity
If continuity is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
Disconnect the connector from the door courtesy switch, and
ground terminal 1 on the wire harness side connector and
check that the warning light lights up.
If the warning light does not light up, inspect the bulb or wire
harness.
LIGHT CONTROL RHEOSTAT
INSPECTION
INSPECT LIGHT CONTROL RHEOSTAT
(a) Connect the positive (+) lead from the battery to terminal 1
and negative lead (±) to terminal 3.
(b) Connect the positive (+) lead from the voltmeter to terminal
2 and negative lead to terminal 3.
(c) Turn the rheostat knob and check that the voltage changes. BE±54
± BODY ELECTRICAL SYSTEMCOMBINATION METER

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

MATRIX CHART OF PROBLEM SYMPTOMS
Proceed to the reference page shown in the matrix chart below for each malfunction symptom and troubleshoot
for each circuit.
HINT: Troubleshooting of the theft deterrent system is based on the premise that the door lock control system
is operating normally. Accordingly, before troubleshooting the theft deterrent system, first make certain that the
door lock control system is operating normally.
Theft Deterrent System
 Details of Problem Inspecting Circuit *1 See Page
  1. Indicator light circuit BE±128
 
 
Th th ft d t t t t b t
 
 2. Luggage compartment door key
lock and unlock switch circuit 
 BE±142
 The theft deterrent system cannot be set 3. Luggage Room Light switch circuit BE±144 
 
 
 4. Door courtesy switch circuit
 
 BE±147
  5. Engine hood courtesy switch circuit BE±148
 The indicator light does not blink when system is set Indicator light circuit BE±128
 
 
 When the
system is
 
 
 
When the back door is
opened by a method other
than the key. 
 
 The system
does not
 
 
 
Luggage compartment door courtesy
switch circuit
 
 
 BE±144
 
 
system is
set 
 When the engine hood is
opened 
 
does not
Operate 
 Engine hood courtesy switch circuit
 
 BE±148
 
 
 
 Horns do not sound 
 Horn relay circuit 
 BE±132
 
 While the system
ii i
 
 
Theft deterrent horn does not
sound 
 
Theft deterrent horn circuit 
 
BE±134
 is in warning
operation Headlights do not flash Headlight control relay circuit BE±136
 o eration Taillights do not flash Taillight control relay circuit BE±138
  The starter cut is not cut off Starter relay circuit BE±130 
 
 When the
System is
 
 
 
It is not cancelled when the
ignition key is Turned to ACC
or ON position
 
 
 Ignition switch circuit
 
 
 BE±140
 
 
 
System is
Set 
 
 
It still operates when the back
door is Opened with the key
 
 
 
Luggage compartment door key lock
and unlock switch circuit
 
 
 
BE±142
 System is still set even when a rear door is open Door courtesy switch circuit BE±147
  Horns sound Horn relay circuit BE±132
 Even when the Theft deterrent horn sounds Theft deterrent horn circuit BE±134
 

Even when the
System is not set 
Headlights stay on 
Headlight control relay circuit 
BE±136 
 
 
 Taillights stay on
 
 Taillight control relay circuit
 
 BE±138
*1
: If numbers are given to the circuit proceed with troubleshooting in the order indicated by those numbers.
± BODY ELECTRICAL SYSTEMBE±123THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM