1986 TOYOTA SUPRA steering wheel

INSPECTION PROCEDURE
(See page EG±510)
(1) Shift the shift lever to N position.
(2) Jack up one of the rear wheels.
(3) Connect SST (check harness ªAº).
(See page
EG±510)
(4) Disconnect power steering ECU connector
and cruise control ECU connector.
(5) Turn ignition switch ON.
Measure voltage between terminal SP1 of engine
control module connector and body ground when
the wheel is turned slowly.
Voltage is generated intermittently.
Check voltage between terminal SP1 of engine control module connector
and body ground.
Check and replace engine control module.
Repair or replace harness or connector between
ECM and telltale light RH.
Repair or replace harness or connector between
telltale light RH and No.1 vehicle speed sensor.
Replace No.1 vehicle speed sensor.
Check operation of odometer and trip meter (telltale light RH
(See page Be±48)).
Check operation of No.1 vehicle speed sensor (See page BE±46).
EG±558± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING

INSPECTION PROCEDURE
(See page
EG±404)
(See page BE±48)).
Check voltage bertween terminal SP1 of engine control module connector
and body ground.
Check and replace engine control module.
(1) Shift the shift lever to N position.
(2) Jack up one of the rear wheel.
(3) Connect SST (check harness ªAº).
(See page EG±404)
SST 09990±01000
(4) Disconnect power steering ECU connector
and cruise control ECU connector.
(5) Turn ignition switch ON.
Measure voltage between terminal SP1 of engine
control module connector and body ground when
the wheel is turned slowly.
Voltage is generated intermittently.
Repair or replace harness or connector between
ECM and telltale light RH.
Check operation of odometer and trip meter (telltale light RH
(See page
BE±48)).
Check operation of No.1 vehicle speed sensor (See page BE±46).
Replace No.1 vehicle speed sensor.
Repair or replace harness or connector between
telltale light RH and No.1 vehicle speed sensor.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±447

28
ELECTRICAL WIRING ROUTING
Position of Parts in Instrument Panel
A 12 A/C Amplifier B 5 Blower Motor Control Relay
A 13 A/C Amplifier B 6 Buckle SW LH
A 14 A/C Amplifier B 7 Buckle SW RH
A 15 A/C Evaporator Temp. Sensor
A 16 A/C Room Temp. Sensor C 5 Center Airbag Sensor Assembly
A 17 A/C Solar Sensor C 6 Cigarette Lighter
A 18 ABS ECU C 7 Cigarette Lighter Illumination
A 19 ABS ECU C 8 Clock
A 20 ABS and Traction ECU C 9 Clutch Start SW
A 21 ABS and Traction ECU C 10 Combination Meter
A 22 ABS and Traction ECU C 11 Combination Meter
A 23 ABS Lateral Acceleration Sensor C 12 Combination Meter
A 24 Air Inlet Control Servo Motor C 13 Combination SW
A 25 Air Mix Control Servo Motor C 14 Combination SW
A 26 Air Vent Mode Control Servo Motor C 15 Cruise Control Clutch SW
A 27 Airbag Squib (Steering Wheel Pad) C 16 Cruise Control ECU
A 28 Airbag Squib (Front Passenger Airbag Assembly)
A 29 Ashtray Illumination D 5 Data Link Connector 2 (TDCL)
A 30 Auto Antenna Control Relay D 6 Daytime Running Light Relay (Main)
D 7 Diode (for Interior Light)
B 3 Blower Motor D 8 Diode (for Idle-Up)
B 4 Blower Motor Control Relay

197
SRS (SUPPLEMENTAL RESTRAINT SYSTEM)
NOTICE: When inspecting or repairing the SRS (supplemental restraint system), perform the operation in
accordance with the following precautionary instructions and the procedure and precautions in the Repair
Manual for the applicable model year.

Malfunction symptoms of the supplemental restraint system are difficult to confirm, so the diagnostic trouble
codes become the most important source of information when troubleshooting.
When troubleshooting the supplemental restraint system, always inspect the diagnostic trouble codes before
disconnecting the battery.

Work must be started after 90 seconds from the time the Ignition SW is set to the ªLOCKº position and the
negative (±) terminal cable is disconnected from the battery.
(The supplemental restraint system is equipped with a back±up power source so that if work is started within
90 seconds of disconnecting the negative (±) terminal cable of the battery, the SRS may be activated.)
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 contents memorized by each memory system.
When work is finished, reset the clock and audio system 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.

When removing the steering wheel pad or handling a new steering wheel pad, keep the pad upper surface
facing upward. Also, lock the lock lever of the twin lock type connector at the rear of the pad and take care
not to damage the connector.
(Storing the pad with its metallic surface up may lead to a serious accident if the SRS inflates for some reason.)

Always store a removed or new front passenger airbag assembly with the airbag door facing up. Storing the
airbag assembly with the airbag door facing down could cause a serious accident if the airbag inflates.

Store the steering wheel pad where the ambient temperature remains below 93°C (200°F), without high
humidity and away from electrical noise.

Never use SRS parts from another vehicle. When replacing SRS parts, replace them with new parts.

Never disassemble and repair the steering wheel pad, front passenger airbag assembly, center airbag sensor
assembly or front airbag sensors.

Before repairing the body, remove the airbag sensors if during repair shocks are likely to be applied to the
sensors due to vibration of the body or direct tapping with tools or other parts.

Do not reuse a steering wheel pad or front airbag sensors.
After evaluating whether the center airbag sensor assembly is damaged or not, decide whether or not to reuse
it. (See the Repair Manual for the method for evaluating the center airbag sensor assembly.)

When troubleshooting the supplemental restraint system, use a high±impedance (Min. 10k
/V) tester.

The wire harness of the supplemental restraint system is integrated with the cowl No. 2 wire harness
assembly.
The vehicle wiring harness exclusively for the airbag system is distinguished by corrugated yellow tubing, as
are the connectors.

Do not measure the resistance of the airbag squibs.
(It is possible this will deploy the airbag and is very dangerous.)

If the wire harness used in the supplemental restraint system is damaged, replace the whole wire harness
assembly.
When the connector to the front airbag sensors can be repaired alone (when there is no damage to the wire
harness), use the repair wire specially designed for the purpose.
(Refer to the Repair Manual for the applicable Model year for details of the replacement method.)

INFORMATION LABELS (NOTICES) are attached to the periphery of the SRS components. Follow the
instructions on the notices.

201
*THE SRS (SUPPLEMENTAL RESTRAINT SYSTEM) IS A DRIVER AND FRONT PASSENGER PROTECTION DEVICE WHICH HAS A
SUPPLEMENTAL ROLE TO THE SEAT BELTS.
WHEN THE IGNITION SW IS TURNED TO ACC OR ON, CURRENT FROM THE CIG FUSE FLOWS TO TERMINAL 14 OF THE CENTER
AIRBAG SENSOR ASSEMBLY. ONLY WHEN THE IGNITION SW IS ON, THE CURRENT FLOWS FROM THE IGN FUSE TO TERMINAL 13.
IF AN ACCIDENT OCCURS WHILE DRIVING, WHEN DECELERATION CAUSED BY A FRONTAL IMPACT IS DETECTED BY EACH SENSOR
AND SWITCH, AND THE FRONTAL IMPACT EXCEEDS A SET LEVEL (WHEN THE SAFING SENSOR BUILT INTO THE CENTER AIRBAG
SENSOR ASSEMBLY IS ON AND THE CENTER AIRBAG SENSOR IS ON, FRONT AIRBAG SENSORS ARE OFF), CURRENT FROM THE
CIG OR IGN FUSE FLOWS TO TERMINALS 3, 2, OF THE CENTER AIRBAG SENSOR ASSEMBLY " TERMINAL 1 OF THE AIRBAG SQUIB
" TERMINAL 2 " TERMINALS 4, 1, OF THE CENTER AIRBAG SENSOR ASSEMBLY " TERMINAL 5, TERMINAL 6 OR BODY GROUND
" GROUND.
WHEN THE SAFING SENSOR BUILT INTO THE CENTER AIRBAG SENSOR ASSEMBLY IS ON AND THE FRONT AIRBAG SENSOR LH OR
RH IS ON, CENTER AIRBAG SENSOR IS OFF AND CURRENT FROM THE CIG OR IGN FUSE FLOWS TO TERMINALS 3, 2, OF THE
CENTER AIRBAG SENSOR ASSEMBLY " TERMINAL 1 OF THE AIRBAG SQUIB " TERMINAL 2 " TERMINALS 4, 1, OF THE CENTER
AIRBAG SENSOR ASSEMBLY " TERMINAL 8 OR 11 " TERMINAL 1 OF THE FRONT AIRBAG SENSOR " TERMINAL 2 " TERMINAL 9
OR 10 OF THE CENTER AIRBAG SENSOR ASSEMBLY " TERMINAL 5, TERMINAL 6 OR BODY GROUND " GROUND, WHEN THE
SAFING SENSOR BUILT INTO THE CENTER AIRBAG SENSOR ASSEMBLY IS ON, AND THE FRONT AIRBAG SENSOR LH OR RH IS ON
AND CENTER AIRBAG SENSOR IS ON ONE OF THE ABOVE±MENTIONED CIRCUITS IS ACTIVATED SO THAT CURRENT FLOWS TO
THE AIRBAG SQUIBS AND CAUSES THEN TO OPERATE.
THE AIRBAG STORED INSIDE THE STEERING WHEEL PAD IS INSTANTANEOUSLY EXPANDED TO SOFTEN THE SHOCK TO THE
DRIVER.
THE AIRBAG STORED INSIDE THE PASSENGER'S INSTRUMENT PANEL IS INSTANTANEOUSLY EXPANDED TO SOFTEN THE SHOCK
TO THE PASSENGER.
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A2728D 126 (2JZ±GE)F224 (2JZ±GTE)
A2828D 528F 226 (2JZ±GE)
C 528F124 (2JZ±GTE)T 629
D 124 (2JZ±GTE)F 126 (2JZ±GE)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE AND J/B NO. 1 (LEFT KICK PANEL)
1G20COWL WIRE AND J/B NO 1 (LEFT KICK PANEL)1J20COWL WIRE AND J/B NO. 1 (LEFT KICK PANEL)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IF136INSTRUMENT PANEL WIRE AND COWL WIRE (INSTRUMENT PANEL REINFORCEMENT LH)
II138ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IE36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 538INSTRUMENT PANEL WIREI1438INSTRUMENT PANEL WIRE
SYSTEM OUTLINE