reset TOYOTA SUPRA 1995 Service Repair Manual

PRECAUTION
Take care to observe the doing precautions when performing inspections or removal and replacement of
body electrical related parts.
HEADLIGHT SYSTEM
wHalogen bulbs have pressurized gas inside and require special handling. They can burst if scratched or
dropped. Hold a bulb only by its plastic or metal case.
Don't touch the glass part of a bulb with bare hands.
SRS (SUPPLEMENTAL RESTRAINT SYSTEM)
wWork must be started after 90 seconds from the time the ignition switch is turned to the ºLOCKº position
and the negative (±) terminal cable is disconnected from the battery.
wWhen disconnecting any of the connectors in the SRS, be sure to lock the ignition switch and disconnect
the negative (±) terminal cable from the battery first. Since the connectors are twin lock type connectors,
disconnect the connectors only after releasing the first stage lock.
wWhen connecting SRS connectors, be sure to lock them securely. (If the connectors are not locked
securely, the system may not operate when needed.)
wAlways store the steering wheel pad with the pad surface facing upward. (Storing the pad with its metallic
surface up may lead to a serious accident if the SRS inflates for some reason.)
wWhen installing the spiral cable, be sure the vehicle is in the straight ahead condition and confirm that the
spiral cable is in the neutral position when it is installed.
wINFORMATION LABELS (NOTICE) are attached to the periphery of the SRS components. Follow the
NOTICE.
AUDIO SYSTEM
wIf the negative (±) terminal cable is disconnected from the battery, the preset AM, FM 1 and FM 2 stations
stored in memory are erased, so be sure to note the stations and reset them after the battery terminal is
reconnected.
wIf the negative (±) terminal cable is disconnected from the battery, the ºANTI±THEFT SYSTEMº will operate
when the cable is reconnected, but the radio, tape player and CD player will not operate. Be sure to input
the correct ID number so that the radio, tape player and CD player can be operated again.
MOBILE COMMUNICATION SYSTEM
wIf the vehicle is equipped with a mobile communication system, refer to precautions in the IN section. BE±2
± BODY ELECTRICAL SYSTEMPRECAUTION

TROUBLESHOOTING
NOTICE: When replacing the internal mechanism (computer part) of the audio system, be careful
that no part of your body or clothing comes in contact with the terminals of the leads from the IC,
etc. of the replacement part (spare part).
HINT: This inspection procedure is a simple troubleshooting which should be carried out on the vehicle
during system operation and is based on the assumption that the cause of trouble lies with the system com-
ponents (except for the wires and connectors, etc.).
Always inspect the trouble taking the following items into consideration.
w Open or short circuit of the wire harness
w Connector or terminal connection fault
w Troubleshooting items marked *indicate that ºTroubleshooting for ANTI±THEFT SYSTEMº should be
carried out first.
 Problem No.  No power coming in. *1  Power coming in, but radio not operating. 2  Noise present, but AM±FM not operating. 3
  Either speaker does not work. 4
  Woofer speaker does not work. 5
 Radio Either AM or FM does not work. 6
  Reception poor (Volume faint). 6
  Few preset tuning bands. 6
  Sound quality poor. 7
  Cannot set station select button. 8
  Preset memory disappears. 8
  Cassette tape cannot be inserted. 9
Cassette tape inserts, but no power.*10  Power coming in, but tape player not operating. 11  Either speaker does not work. 12 Tape player Woofer speaker does not work. 13 y Sound quality poor (Volume faint). 14  Tape jammed, malfunction with tape speed or auto±reverse. 15  APS, SKIP, RPT buttons not operating. 16
  Cassette tape will not eject. *17
  CD cannot be inserted. 18
  CD inserts, but no power. 19
  Power coming in, but CD player not operating. 20
 CDplayer Sound jumps. 21
 CD player Sound quality poor (Volume faint). 22
  Either speaker does not work. 23
  Woofer speaker does not work. 24
  CD will not eject. 25
No power coming in.26 
Amplifier
 Power coming in, but woofer amplifier (Power amplifier) not operating. 27 Amplifier Either speaker does not work. 28  Woofer speaker does not work. 29
BE±86± BODY ELECTRICAL SYSTEMAUDIO SYSTEM

Poor signals, poor location.
Radio assembly faulty.
Power amplifier faulty.
Go to No. 32.
Is tape player operating normally?Radio assembly faulty?
Speaker faulty.
Radio assembly faulty.
Hissing sound from speaker?Power amplifier faulty. Recheck system after repair.
Radio assembly faulty. Recheck system after repair.
Problem with radio wave signals or
location? (See SYSTEM DESCRIPTION)
Are both AM and FM defective?
Is power for the antenna being output
from the radio assembly.
Is power for the antenna being output
from the power amplifier?
Temporarily install another speaker.
Functions OK?
RadioEITHER AM OR FM DOES NOT WORK, RECEPTION
POOR (VOLUME FAINT), FEW PRESET TUNING BANDS
± BODY ELECTRICAL SYSTEMAUDIO SYSTEMBE±93

Replace fuse.
Radio assembly faulty.Can cassette tape be installed in tape player?
Check RAD No. 1 fuse is OK?
Is +B applied to power amplifier?+B wire harness faulty.
GND faulty.
Is +B applied to radio assembly?+B wire harness faulty.
Power amplifier faulty.
GND faulty.
Power amplifier faulty.
Radio assembly faulty.
Check if GND (wire harness side)
to power amplifier.
Check if GND (wire harness side) to radio
assembly?
CANNOT SET STATION SELECT BUTTON, PRESET
MEMORY DISAPPEARSRadio
± BODY ELECTRICAL SYSTEMAUDIO SYSTEMBE±95

Display E:
ANTI±THEFT SYSTEM
operation condition.
(ID number input error
10 times or more.)Display A:
ID Number is set.Display B
Anti±theft
SystemTROUBLESHOOTING FOR ANTI±THEFT SYSTEM
Turn Ignition key from Lock position to ACC position.
Cancel ID number, refer to each malfunction item.
Take to designated radio
service station.
[ISEC] Display Disappears
After 1 Second.
Normal operation
Refer to each
malfunction item.
(Liquid Crystal Display (LCD) for Audio System)
Cancel ID number, refer to each malfunction item.
ANTI±THEFT SYSTEM operation condition.
[ID number input error 9 times or less.]
Input ID number to cancel ANTI±THEFT SYSTEM, and check display.
Radio switch ON.
ANTI±THEFT SYSTEM not
cancelled.
(ID number input error 9
times or less.)
ANTI±THEFT SYSTEM cancelled.
Check audio system again.
Radio Display
Display BDisplay D
Radio switch ON.
Display EDisplay C"ADisplay BDisplay A " B
Display D
Radio switch ON.Take to designated radio
service station.Refer to each
malfunction item.
Normal
operation
Normal operation.
ID number
input error
time
Blank,
No Illumination
Display B
Display E
Display DDisplay ADisplay C
HINT:
a) Refer to O/M for operation details of ANTI±THEFT SYSTEM.
b) When the ID number has been cancelled, reset the same number after completing the operation,
or inform the customer that it has been cancelled.
± BODY ELECTRICAL SYSTEMAUDIO SYSTEMBE±111

SYSTEM INSPECTION
1. SETTING OF THE THEFT DETERRENT SYSTEM
Setting Conditions
(a) Close all the doors.
(b) Close the engine hood and luggage compartment door.
(c) Remove the ignition key from the ignition key cylinder.
Setting Operation
When any of the following operations (a) or (c) is done, the theft deterrent indicator light will light up as de-
scribed.
(a) Lock the left or right front door using the key.
(All doors are locked by key±interlinked lock operation)
(b) With the rear doors locked and with one of the front doors locked, lock the other front door without
using the key (keyless door lock).
 
 Elapsed time after operation
 
 Indicator light
  Within about 30 seconds  Lights up
  After about 30 seconds  Blinks *1
*1: 1 sec. on, 1 sec. off
HINT: When the theft deterrent system is set, doors cannot be locked or unlocked with the door lock control
switch and the luggage compartment door cannot be unlocked with the luggage compartment door opener
switch.
2. CANCELLING OF THE THEFT DETERRENT SYSTEM IN THE SET CONDITION
Check if the theft deterrent indicator light is blinking.
Cancelling Operation
When any of the following operation (a), (b), (c) or (d) is done, the theft deterrent system is cancelled and
indicator light will go off.
(a) Unlock the left or right front door using the key.
(b) Insert the ignition key in the ignition key cylinder and turn it to the ACC or ON position.
(This is operative only when the theft deterrent system has never operated.)
(c) Unlock the luggage compartment door with the key. *
1
*1: The theft deterrent system is temporarily cancelled only while the luggage compartment door is
open. Approximately 2 seconds after the luggage compartment door is closed, the theft deterrent
system is reset.
± BODY ELECTRICAL SYSTEMTHEFT DETERRENT AND DOOR LOCK CONTROL SYSTEMBE±121

3. CHECK OF THE THEFT DETERRENT SYSTEM OPERATION.
Check if the theft deterrent indicator light is blinking.
When any of the following operations (a) or (b) is done, the system sounds the horns and theft deterrent
horn and flashes the headlights and taillights for about one minute to alert. At the same time, the system
disconnects the starter motor circuit and locks all doors (if all doors are not locked, the system repeats door
locking operation every 2 seconds during the one minute alert time).
(a) Open the engine hood using the engine hood opener lever.
(b) Unlock any of the front or rear doors without key operation.
4. CANCELLING OF THE THEFT DETERRENT SYSTEM IN OPERATING CONDITION.
The theft deterrent operation can be cancelled when any of the following conditions is met:
 No. Condition Cancelling Operation 
 1
 
 Unlock left or right door with the key.
 
 
 2 Unlock doors with wireless door lock control system. 
 3 Insert key into ignition key cylinder and turn it to ACC or ON position. *2
 4 About 1 minute passes after theft deterrent operation begins. Automatic stop *1
*1: In this case, the theft deterrent system resets in about 2 seconds after if all doors are closed.
*
2: The alarm will be off, but the engine will not operate. To restart the engine, see No.1.
ECU TERMINAL VALUES MEASUREMENT
USING TOYOTA BREAK±OUT±BOX AND
TOYOTA HAND±HELD TESTER
1. Hook up the TOYOTA break±out box and TOYOTA handheld
tester to the vehicle.
2. Read the ECU input/output values by following the prompts
on the hand±held tester screen.
HINT: TOYOTA hand±held tester has a ºShapshotº func-
tion. This records the measured values and is effective in
the diagnosis of intermittent problems.
Please refer to the TOYOTA hand±held tester/TOYOTA
break±out±box operator's manual for further details. BE±122
± BODY ELECTRICAL SYSTEMTHEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

DTC 21 23 Speed Sensor Circuit
The speed sensor signal is sent to cruise control ECU as ve-
hicle speed signal.
The rotor shaft is driven by the gear of the transmission. For
each rotation of the shaft, the speed sensor sends a 4±pulse
signal to the combination meter.
This signal is converted inside the combination meter and
sent as a 4±pulse signal to the cruise control ECU.
The ECU calculates the vehicle speed from this pulse fre-
quency.
CIRCUIT DESCRIPTION
Speed signal is not input to the ECU while
cruise control is set..
Vehicle speed decrease 16 km/h or more
than preset speed.
Vehicle speed sensor pulse is abnormal.
Speed sensor
Combination meter
Harness or connector between speed sen-
sor and combination meter, combination
meter and ECU.
ECU
Actuator
Speed sensor
Harness or connector in OD and SPD cir-
cuit (Open or short intermittently)
ECU
± BODY ELECTRICAL SYSTEMCRUISE CONTROL SYSTEMBE±177

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

GENERAL DESCRIPTION
The SUPRA is equipped with an SRS (Supplemental Restraint System), which comprises a driver
airbag, and front passenger airbag if fitted. Failure to carry out service operations in the correct
sequence could cause the SRS to unexpectedly deploy during servicing, possibly leading to a seri-
ous accident. Further, if a mistake is made in servicing the SRS, it is possible the SRS may fail to
operate when required. Before performing servicing (including removal or installation of parts, in-
spection or replacement), be sure to read the following items carefully, then follow the correct pro-
cedure described in the repair manual.
1. Malfunction symptoms of the SRS are difficult to confirm, so the diagnostic trouble codes become the most
important source of information when troubleshooting. When troubleshooting the SRS, always inspect the
diagnostic trouble codes before disconnecting the battery.
(See page RS±44)
2. Work must be started after 90 seconds from the time the ignition switch is turned to the ºLOCKº
position and the negative (±) terminal cable is disconnected from the battery.
(The SRS is equipped with a back±up power source so that if work is started within 90 seconds of
disconnecting the negative (±) terminal cable from the battery, the SRS may deploy.)
When the negative (±) terminal cable is disconnected from the battery, memory of the clock and audio sys-
tems will be canceled. So before starting work, make a record of the contents memorized by the audio
memory system. When work is finished, reset the audio systems as before and adjust the clock. 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, front airbag sensors and center airbag sensor assembly should be inspected.
(See pages RS±10, 20, 30, and 33)
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 steering wheel pad, front passenger airbag assembly, front airbag
sensors or center airbag sensor assembly in order to reuse it.
7. If the steering wheel pad, front passenger airbag assembly, front airbag sensors or center airbag sensor
assembly 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 steering wheel pad, front passenger airbag assembly, front airbag sensors or center
airbag sensor assembly directly to hot air or flames.
9. Use a volt/ohmmeter with high impedance (10 k
/V minimum) for troubleshooting the system's electrical
circuits.
10. Information labels are attached to the periphery of the SRS components. Follow the instructions on the
notices.
11. After work on the SRS is completed, check the SRS warning light.
(See page RS±44)
12. If the vehicle is equipped with a mobile communication system, refer to the precaution in the IN section. RS±2
± SUPPLEMENTAL RESTRAINT SYSTEMGENERAL DESCRIPTION