1995 TOYOTA SUPRA warning lights

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

ABS Warning Light Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, it lights the ABS warning light while at the same time prohibiting ABS control.
At this time, the ECU records a diagnostic trouble code in memory.
After removing the short pin of the DLC1, connect terminals Tc and E1 of the DLC1 or DLC2 to make the
ABS warning light to blink and output the diagnostic trouble code.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±107

BR±134
BR±137
BR±137
BR±138
BR±138
BR±138
BR±138
BR±142
BR±145
BR±147
BR±149
BR±149
BR±152
BR±152
BR±155
BR±156
BR±157
Open or short in sub±throttle actuator circuit
Step motor does not move to a position decided by ECU
Sub±throttle valve does not move even when the sub±throttle
valve is controlled to fully open position by ECU
Right front wheel speed sensor signal malfunction
Left front wheel speed sensor signal malfunction
Right rear wheel speed sensor signal malfunction
Left rear wheel speed sensor signal malfunction
Low battery positive voltage or abnormally high battery
positive voltage
Malfunction in ABS or TRAC (BRAKE) control system
Open or short in NE signal circuit
Main throttle position sensor circuit malfunction
Open or short in main throttle position sensor circuit
Sub±throttle position sensor circuit malfunction
Open or short in sub±throttle position sensor circuit
Engine & ECT system malfunction
ECM communication circuit malfunction
ABS & TRAC ECU communication circuit malfunction
Malfunction in TRAC ECU
DiagnosisCodeTRAC Indicator Light
Blinking PatternSee page
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the diagnostic trouble code check, check the circuit listed for that code
in the table below and proceed to the relevant page.
HINT: If the TRAC indicator light lights up and the TRAC indicator light does not blink when the DTC is checked,
check the blinking pattern of the ABS warning light and troubleshoot the ABS system.
*
1: If a malfunction is detected in ABS the TRAC OFF indicator light lights up instead of the TRAC indicator
light.
*
2: The TRAC indicator light does not light up even if an error is detected
*3: If a malfunction is detected, the TRAC OFF indicator light lights up instead of the TRAC indicator light.
*4: Depending on the malfunction, the TRAC indicator light does not light up. BR±128
± BRAKE SYSTEMTRACTION CONTROL SYSTEM (TRAC)

TRAC OFF Indicator TRAC Cut Switch Circuit
CIRCUIT DESCRIPTION
This is the TRAC control main switch. When the TRAC cut switch is pushed on, TRAC control goes off and the
TRAC OFF indicator lights up. This indicator is also used for warnings when the trouble occurs.
± BRAKE SYSTEMTRACTION CONTROL SYSTEM (TRAC)BR±159

There are some maintenance and inspection
items which are considered to be the owner's re-
sponsibility. They can be performed by the owner
or be can have them done at a service shop.
These items include those which should be
checked on a daily basis, those which, in most
cases, do not require (special) tools and those
which are considered to be reasonable for the
owner to perform. Items and procedures for gen-
eral maintenance are as follows:
OUTSIDE VEHICLE
1. TIRES
(a) Check the pressure with a gauge. Adjust if
necessary.
(b) Check for cuts, damage, uneven or excessive
wear.
2. WHEEL NUTS
When checking the tires, check the nuts for
looseness or for missing nuts. If necessary,
tighten them.
3. WINDSHIELD WIPER BLADES
Check for wear or cracks whenever they do not
wipe clean. Replace if necessary.
4. FLUID LEAKS
(a) Check underneath for leaking fuel, oil, water or
other fluid.
(b) If you smell gasoline fumes or notice any leak,
have the cause found and corrected.
5. DOORS AND ENGINE HOOD
(a) Check that all doors including the trunk lid
operate smoothly, and that all latches lock
securely.
(b) Check that the engine hood secondary latch
secures the hood from opening when the
primary latch is released.
INSIDE VEHICLE
6. LIGHTS
(a) C h e c k t h a t t h e headlights, stop lights,
tail±lights, turn signal lights, and other lights
are all working.
(b) Check the headlight aiming.7. WARNING LIGHT AND BUZZERS
Check that all warning lights and buzzers
function properly.
8. HORN
Check that it is working.
9. WINDSHIELD GLASS
Check for scratches, pits or abrasions.
10. WINDSHIELD WIPER AND WASHER
(a) Check operation of the wipers and washer.
(b) Check that the wipers do not streak.
11. WINDSHIELD DEFROSTER
Check that the air comes out from the defrost-
er outlet when operating the heater air condi-
tioner at defroster mode.
12. REAR VIEW MIRROR
Check that it is mounted securely.
13. SUN VISORS
Check that they move freely and are
mounted securely.
14. STEERING WHEEL
Check that it has the specified freeplay. Be
alert for changes in steering condition, such
as excessive steering effort, excessive free-
play or strange noise.
15. SEATS
(a) Check that all front seat controls such as seat
adjusters, seatback recliner, etc. operate
smoothly.
(b) Check that all latches lock securely in any
position.
(c) Check that the locks hold securely in any
latched position.
(d) Check that the head restraints move up and
down smoothly and that the locks hold
securely in any latched position.
(e) For folding±down rear seat backs, check that
the latches lock securely.
16. SEAT BELTS
(a) Check that the seat belt system such as
buckles, retractors and anchors operate
properly and smoothly.
(b) Check that the belt webbing is not cut, frayed,
worn or damaged.
17. ACCELERATOR PEDAL
Check the pedal for smooth operation and
uneven pedal effort or catching.
GENERAL MAINTENANCE
± MAINTENANCEGENERAL MAINTENANCEMA±17