1995 TOYOTA SUPRA warning light

CUSTOMER PROBLEM ANALYSIS CHECK SHEET
 
 TRAC Check Sheet
Inspector 's
Name:
   Registration No. 
 
 Customer 's Name
 
 
 
 Registration Year
 
 //
 
 
 
 
 
 Frame No. 
 
 
 
Date Vehicle
Brought In 
 // 
 Odometer Reading 
 
km
Miles
 
 
 
Date Problem First Occurred
 
 
 
//
 
  Frequency Problem Occurs 
  Continuous  Intermittent ( Times a day)

 
 
 
 TRAC does not operate. (Wheels spin when starting rapidly).
 
 
  Symptoms
 
 
 
TRAC Indicator
Light Abnormal
 
 
 Remains ON Blinks Does not Light Up
 
 
 
 
 
 
TRAC OFF Indicator
Light Abnormal
 
 
 
Remains ON Does not Light Up
 
 
Ch k It
 
 ABS Warning LIght 
 Normal Malfunction Code (Code )
 
 
Check Item 
 
Malfunction
Indicator Lamp 
 NormalMalfunction Code (Code )
 
 Diagnostic
Tro ble Code
 
 1st Time
 
 Normal CodeMalfunction Code (Code )
 
 
 
Trouble Code
Check 
 
 
2nd Time
 
 
 
Normal CodeMalfunction Code (Code )
± BRAKE SYSTEMTRACTION CONTROL SYSTEM (TRAC)BR±125

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)

ECU TERMINALS STANDARD VALUE
ABS & TRAC ECU:
ConditionSTD Voltage (V)Symbols
(Terminals No.)
Always
IG switch ON
IG switch ON, ABS warning light OFF
IG switch ON
IG switch ON, TRAC and TRAC OFF indicator light OFF
IG switch ON
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, TRAC and TRAC OFF indicator light OFF
IG switch ON, TRAC and TRAC OFF indicator light OFF
IG switch ON, ABS warning light ON
IG switch ON, ABS warning light OFF
IG switch ON, PKB switch ON
Fluid in M/C reservoir above MIN level.
IG switch ON, PKB switch OFF
Fluid in M/C reservoir above MIN level.
IG switch ON
Fluid in M/C reservoir above MIN level.
Stop light switch OFF
Stop light switch ON
IG switch ON, ABS warning light OFF
BR±130± BRAKE SYSTEMTRACTION CONTROL SYSTEM (TRAC)

(See page IN±30).
(See page IN±30).
(See page BR±62).
Remove front fender splash shield.
Disconnect speed sensor connector.
Measure resistance between terminals 1 and 2 of
speed sensor connector.
Resistance: 0.7 ± 1.7 k

Resistance: 1 M
or higher
Remove rear seat cushion, seat back and quarter
trim panel.
Disconnect speed sensor connector.
Measure resistance between terminals 1 and 2 of
speed sensor connector.
Resistance: 0.7 ± 1.7 k

Measure resistance between terminals 1 and 2 of
speed sensor connector and body ground.
Resistance: 1 M
or higher
Repair or replace harness or connector.
Check speed sensor.
Check for open and short in harness and connector between terminals FRO,
FLO, RRO, RLO of ABS & TRAC ECU and TRAC ECU (See page IN±30).
Front
Rear
Replace speed sensor.
NOTICE: Check the speed sensor signal last (See page BR±62).
Check for open and short in harness and connector between each speed
sensor and ECU (See page IN±30).
Repair and replace harness or connector.
INSPECTION PROCEDURE
HINT: If the same code is output from the ABS warning light, troubleshoot the ABS first. BR±140
± 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

TRAC Indicator Light Circuit
CIRCUIT DESCRIPTION
The TRAC indicator blinks during TRAC operation.
This indicator is also used for warnings when the trouble occurs and for displaying diagnostic trouble
codes.
Repair or replace harness or connector.
Check and replace TRAC ECU.
Repair circuit indicated by the code output.
Check diagnostic trouble code (See page BR±126).
INSPECTION PROCEDURES
Troubleshoot in accordance with flow chart instructions for each trouble symptom.
TRAC Indicator light does not light up
Go to Combination Meter Troubleshooting on page BE±43.
TRAC Indicator light remains ON
Check for short in harness and connector between TRAC ECU and TRAC
indicator light (See page IN±30).
Indicator light remains ONOutput
NG Code
BR±162± BRAKE SYSTEMTRACTION CONTROL SYSTEM (TRAC)

wCheck that the arrow mark on the belt tensioner falls
within area A of the scale.
If it is outside area A, replace the drive belt.
HINT:
wWhen a new belt is installed, it should lie within area B.
If not, the drive belt is not correct.
wAfter installing a drive belt, check that it fits properly in
the ribbed grooves.
wCheck by hand to confirm that the belt has not slipped
out of the groove on the bottom of the pulley.
4. REMOVE ENGINE UNDER COVER
5. VISUALLY CHECK GENERATOR WIRING AND LISTEN
FOR ABNORMAL NOISES
(a) Check that the wiring is in good condition.
(b) Check that there is no abnormal noise from the generator
while the engine is running.
6. CHECK CHARGE WARNING LIGHT CIRCUIT
(a) Warm up the engine and then turn it off.
(b) Turn off all accessories.
(c) Turn the ignition switch ºONº. Check that the charge warning
light is lit.
(d) Start the engine. Check that the light goes off. If the light does
not go off as specified, troubleshoot the charge light circuit.
7. INSPECT CHARGING CIRCUIT WITHOUT LOAD
HINT: If a battery/generator tester is available, connect the
tester to the charging circuit as per manufacturer's instruc-
tions.
(a) If a tester is not available, connect a voltmeter and ammeter
to the charging circuit as follows:
wDisconnect the wire from terminal B of the generator,
and connect it to the negative (±) probe of the ammeter.
± CHARGING SYSTEMON±VEHICLE INSPECTIONCH±5

When the negative (±) terminal cable is disconnected from
the battery, memory of the clock and audio systems will be
cancelled. So before starting work, make a record of the con-
tents memorized by the audio memory system. When work
is finished, reset the audio systems as before and adjust the
clock.
This vehicle has power tilt and power telescopic steering,
power seat, power outside rear view mirror and power shoul-
der belt anchorage, which are all equipped with memory
function, it is not possible to make a record of the memory
contents. So when the work is finished, therefore it will be
necessary to explain this fact to the customer, and ask the
customer to adjust the features and reset the memory.
To avoid erasing the memory of each memory system, never
use a back±up power supply from outside the vehicle.
3. Even in cases of a minor collision where the SRS does not
deploy, the steering wheel pad, front passenger airbag
assembly and front airbag sensors should be inspected (See
pages RS±10, 20, 30).
4. Never use SRS parts from another vehicle. When replacing
parts, replace them with new parts.
5. Before repairs, remove the airbag sensors if shocks are likely
to be applied to the sensors during repairs.
6. Never disassemble and repair the front airbag sensors,
center airbag sensor assembly, steering wheel pad or front
passenger airbag assembly in order to reuse it.
7. If the front airbag sensors, center airbag sensor assembly,
steering wheel pad, front passenger airbag assembly or seat
belt pretensioners have been dropped, or if there are cracks,
dents or other defects in the case, bracket or connector,
replace them with new ones.
8. Do not expose the front airbag sensors, center airbag sensor
assembly, steering wheel pad, front passenger airbag
assembly or seat belt pretensioners directly to hot air or
flames.
9. Use a volt/ohmmeter with high impedance (10 k
/V
minimum) for troubleshooting of the electrical circuit.
10. Information labels are attached to the periphery of the SRS
components. Follow the instructions on the notices.
11. After work on the supplemental restraint system is
completed, perform the SRS warning light check (See page
RS±44).
± INTRODUCTIONPRECAUTIONIN±11