Page 57 of 1807

IN04E-02
BO4111
Negative Cable
IN-10
- INTRODUCTIONFOR ALL OF VEHICLES
10 Author: Date:
1997 SUPRA (RM502U)
FOR ALL OF VEHICLES
PRECAUTION
1. FOR VEHICLES EQUIPPED WITH SRS AIRBAG
(a) The TOYOTA SUPRA is equipped with an SRS (Supple-
mental Restraint System), such as the driver airbag, front
passenger airbag.
Failure to carry out service operations in the correct se-
quence could cause the supplemental restraint system to
unexpectedly deploy during servicing, possibly leading to
a serious accident.
Further, if a mistake is made in servicing the supplemental
restraint system, it is possible the SRS may fail to operate
when required. Before servicing (including removal or
installation of parts, inspection or replacement), be sure
to read the following items carefully, then follow the cor-
rect procedure described in this manual.
(b) GENERAL NOTICE
(1) Malfunction symptoms of the supplemental re-
straint system are difficult to confirm, so the diag-
nostic 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 (See page DI-555).
(2) Work must be started after 90 seconds from the
time the ignition switch is turned to the ºLOCKº posi-
tion and the negative (-) terminal cable is discon-
nected 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 neg-
ative (-) terminal cable from the battery, the SRS
may deploy.)
When the negative (-) terminal cable is discon-
nected 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
the audio memory system. Then when work is fin-
ished, reset the clock and audio systems as before.
To avoid erasing the memory of each memory sys-
tem, never use a back-up power supply from out-
side the vehicle.
Page 58 of 1807

B02917
- INTRODUCTIONFOR ALL OF VEHICLES
IN-1 1
11 Author: Date:
1997 SUPRA (RM502U)
(3) Even in cases of a minor collision where the SRS
does not deploy, the steering wheel pad, front pas-
senger airbag assembly and front airbag sensor
should be inspected (See page SR- 8, RS- 22,
RS-34).
(4) Never use SRS parts from another vehicle. When
replacing parts, replace them with new parts.
(5) Before repairs, remove the airbag sensor if shocks
are likely to be applied to the sensor during repairs.
(6) Never disassemble and repair the airbag sensor as-
sembly, steering wheel pad or front passenger air-
bag assembly in order to reuse it.
(7) If the airbag sensor assembly, steering wheel pad
or front passenger airbag assembly have been
dropped, or if there are cracks, dents or other de-
fects in the case, bracket or connector, replace
them with new ones.
(8) Do not expose the airbag sensor assembly, steer-
ing wheel pad and front passenger airbag assembly
directly to hot air or flames.
(9) Use a volt/ohmmeter with high impedance (10 kW/V
minimum) for troubleshooting of the electrical cir-
cuit.
(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, check the SRS warning light (See page
RS-1).
(c) SPIRAL CABLE (in Combination Switch)
The steering wheel must be fitted correctly to the steering
column with the spiral cable at the neutral position, other-
wise cable disconnection and other troubles may result.
Refer to of this manual concerning correct steering wheel
installation.
Page 59 of 1807

Z13953
Example:Wrong Correct
Z13950
Example: IN-12
- INTRODUCTIONFOR ALL OF VEHICLES
12 Author: Date:
1997 SUPRA (RM502U)
(d) STEERING WHEEL PAD (with Airbag)
(1) When removing the steering wheel pad or handling
a new steering wheel pad, it should be placed with
the pad top surface facing up.
In this case, the twin-lock type connector lock lever
should be in the locked state and care should be
taken to place it so the connector will not be dam-
aged. In addition do not store a steering wheel pad
on top of another one. Storing the pad with its metal-
lic surface facing upward may lead to a serious acci-
dent if the airbag inflates for some reason.
(2) Never measure the resistance of the airbag squib.
(This may cause the airbag to deploy, which is very
dangerous.)
(3) Grease should not be applied to the steering wheel
pad and the pad should not be cleaned with deter-
gents of any kind.
(4) Store the steering wheel pad where the ambient
temperature remains below 93°C (200°F), without
high humidity and away from electrical noise.
(5) When using electric welding, first disconnect the air-
bag connector (yellow color and 2 pins) under the
steering column near the combination switch con-
nector before starting work.
(6) When disposing of a vehicle or the steering wheel
pad alone, the airbag should be deployed using an
SST before disposal (See page RS-1 1).
Carry out the operation in a safe place away from
electrical noise.
Page 60 of 1807

Z13952
Example:Correct Wrong
Z13951
Example:
- INTRODUCTIONFOR ALL OF VEHICLES
IN-13
13 Author: Date:
1997 SUPRA (RM502U)
(e) FRONT PASSENGER AIRBAG ASSEMBLY
(1) Always store a removed or new front passenger air-
bag assembly with the airbag deployment direction
facing up.
Storing the airbag assembly with the airbag deploy-
ment direction facing down could cause a serious
accident if the airbag inflates.
(2) Never measure the resistance of the airbag squib.
(This may cause the airbag deploy, which is very
dangerous.)
(3) Grease should not be applied to the front passen-
ger airbag assembly and the airbag door should not
be cleaned with detergents of any kind.
(4) Store the airbag assembly where the ambient tem-
perature remains below 93°C (200°F), without high
humidity and away from electrical noise.
(5) When using electric welding, first disconnect the air-
bag connector (yellow color and 2 pins) installed on
the glove compartment finish plate at the left side of
the glove compartment before starting work.
(6) When disposing of a vehicle or the airbag assembly
alone, the airbag should be deployed using an SST
before disposal (See page RS-24).
Perform the operation in a safe place away from
electrical noise.
Page 61 of 1807

IN-14
- INTRODUCTIONFOR ALL OF VEHICLES
14 Author: Date:
1997 SUPRA (RM502U)
(f) AIRBAG SENSOR ASSEMBLY
(1) Never reuse the airbag sensor assembly involved
in a collision when the SRS has deployed.
(2) The connectors to the airbag sensor assembly
should be connected or disconnected with the sen-
sor mounted on the floor. If the connectors are con-
nected or disconnected while the airbag sensor as-
sembly is not mounted to the floor, it could cause
undesired ignition of the supplemental restraint sys-
tem.
(3) Work must be started after 90 seconds from the
time the ignition switch is turned to the ºLOCKº posi-
tion and the negative (-) terminal cable is discon-
nected from the battery, even if only loosening the
set bolts of the airbag sensor assembly.
(g) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the cowl wire har-
ness assembly and floor wire harness assembly. The
wires for the SRS wire harness are encased in a yellow
corrugated tube. All the connectors for the system are
also a standard yellow color. If the SRS wire harness be-
comes disconnected or the connector becomes broken
due to an accident, etc., repair or replace it as shown on
page RS-38.
2. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
If large amounts of unburned gasoline flow into the converter, it may overheat and create a fire hazard. To
prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off and prolonged braking.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
3. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
(a) For vehicles with mobile communication systems such as two-way radios and cellular telephones, ob-
serve the following precautions.
(b) Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic sys-
tem.
Page 62 of 1807

B02572
TRAC OFF
Indicator Light
TRAC Cut
Switch
N19405
- INTRODUCTIONFOR ALL OF VEHICLES
IN-15
15 Author: Date:
1997 SUPRA (RM502U)
(c) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the vehicle's
electronics systems. For details about ECU and sensors locations, refer to the section on the applica-
ble component.
(d) Do not wind the antenna feeder together with the other wiring. As much as possible, also avoid running
the antenna feeder parallel with other wire harnesses.
(e) Confirm that the antenna and feeder are correctly adjusted.
(f) Do not install powerful mobile communications system.
4. FOR USING OBDII SCAN TOOL OR TOYOTA HAND-HELD TESTER
Observe the following for safety reasons:
Before using the OBDII scan tool or TOYOTA hand-held tester, the OBDII scan tool's instruction
book or TOYOTA hand-held tester's operator manual should be read thoroughly.
Be sure to route all cables securely when driving with the OBDII scan tool or TOYOTA hand-held
tester connected to the vehicle. (i.e. Keep cables away from feet, pedals, steering wheel and shift
lever.)
Two persons are required when test driving with the OBDII scan tool or TOYOTA hand-held tes-
ter, one person to drive the vehicle and one person to operate the OBDII scan tool or TOYOTA
hand-held tester.
5. FOR VEHICLES EQUIPPED WITH TRACTION CON-
TROL (TRAC) SYSTEM
When using a 2 wheel drum tester such as a speedometer tes-
ter or chassis dynamometer, etc., or jacking up the rear wheels
and driving the wheels, always push in the TRAC cut (ºTRAC
OFFº) switch and turn the TRAC system OFF.
(a) Confirm TRAC system is OFF
(1) Press the TRAC cut (ºTRAC OFFº) switch.
(2) Check that the TRAC OFF indicator light comes on
when the TRAC system is turned off by the TRAC
cut switch.
HINT:
The TRAC OFF indicator light should always operate right after
the engine is restarted.
(3) Begin measurements.
Page 63 of 1807
N19108
F01960
2JZ-GE
2JZ-GTENo.2 Joint No.3 Joint
A - B = -1°09' ± 36'
No.2 Joint
A - B = -1°09' ± 36'B - C = 44' ± 36'
No.3 Joint
B - C = 44' ± 36'Joint Angle- :
+ :
A
B
C
A
B
C>>
IN-16
- INTRODUCTIONFOR ALL OF VEHICLES
16 Author: Date:
1997 SUPRA (RM502U)
(4) Press the TRAC cut switch again to change the
TRAC to oprative and check that the TRAC OFF in-
dicator light goes off.
HINT:
The SLIP indicator light blinks when the TRAC system is opera-
tive.
6. INSPECTION AND ADJUSTMENT OF JOINT ANGLE DURING REMOVAL AND INSTALLATION OF
PROPELLER SHAFT
When performing operations which involve the removal and installation of the propeller shaft, always check
the joint angle. Make adjustments if necessary (See page PR-14).
Page 64 of 1807

IN04F-02
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-17
17 Author: Date:
1997 SUPRA (RM502U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the TOYOTA SUPRA. In general, the ECU controlled
system is considered to be a very intricate system requiring a high level of technical knowledge and expert
skill to troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshoot-
ing of these systems is not complex. If you have adequate understanding of the system and a basic knowl-
edge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem.
This manual is designed through emphasis of the above standpoint to help service technicians perform ac-
curate and effective troubleshooting, and is compiled for the following major ECU controlled systems:
SystemPage
1. Engine (2JZ-GE)DI-1
2. Engine (2JZ-GTE)DI-145
3. Automatic Transmission (2JZ-GE)DI-316
4. Automatic Transmission (2JZ-GTE)DI-371
5. Anti-Lock Brake SystemDI-440
6. ABS & Traction control SystemDI-499
7. Supplemental Restraint SystemDI-555
8. Theft Deterrent SystemDI-608
9. Cruise Control SystemDI-660
11. Air Conditioning SystemDI-71 1
The troubleshooting procedure and how to make use of it are described on the above pages.
FOR USING OBDII SCAN TOOL OR TOYOTA HAND-HELD TESTER
Before using the OBDII scan tool or TOYOTA hand-held tester, the OBDII scan tool's instruction book
or TOYOTA hand-held tester's operator manual should be read thoroughly.
If the OBDII scan tool or TOYOTA hand-held tester cannot communicate with ECU controlled systems
when you have connected the cable of the OBDII scan tool or TOYOTA hand-held tester to DLC3,
turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool
side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Busline) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outlined in the Tester Operator's
Manual.