Page 9 of 1202

IN07J-05
BO4111
Negative Cable
- INTRODUCTIONFOR ALL OF VEHICLES
IN-9
9 Author: Date:
1996 TERCEL (RM440U)
FOR ALL OF VEHICLES
PRECAUTION
1. FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND
SEAT BELT PRETENSIONER
(a) The TERCEL is equipped with an SRS (Supplemental
Restraint System), such as the driver airbag and 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 negative (-) terminal cable from
the battery (See page DI-148).
(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 each 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 anoth-
er battery.
Page 10 of 1202

R09725Match Marks
IN-10
- INTRODUCTIONFOR ALL OF VEHICLES
10 Author: Date:
1996 TERCEL (RM440U)
(3) Even in cases of a minor collision where the SRS
does not deploy, the steering wheel pad (See page
RS-9) and front passenger airbag assembly (See
page RS-22) should be inspected.
(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 attached to the sensor during re-
pairs.
(6) Never disassemble and repair the airbag sensor as-
sembly, steering wheel pad or front passenger air-
bag.
(7) If the airbag sensor assembly, steering wheel pad
or front passenger airbag 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 directly expose the airbag sensor assembly,
steering wheel pad or front passenger airbag 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 is completed, check the SRS warning
light for the supplemental restraint system (See
page DI-148).
(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 RS-19 of this manual concerning correct steer-
ing wheel installation.
Page 11 of 1202

Z13953
Example:CORRECT WRONG
Z13950
Example:
- INTRODUCTIONFOR ALL OF VEHICLES
IN-1 1
11 Author: Date:
1996 TERCEL (RM440U)
(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.
Storing the pad with its metallic surface facing up-
ward may lead to a serious accident if the airbag de-
ploys for some reason. In addition do not store a
steering wheel pad on top of another one.
(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 attached to the steering
wheel pad and the pad should not be cleaned with
detergents 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).
Perform the operation in a safe place away from
electrical noise.
Page 12 of 1202

Z13952
Example:CORRECT WRONG
Z13951
Example:
IN-12
- INTRODUCTIONFOR ALL OF VEHICLES
12 Author: Date:
1996 TERCEL (RM440U)
(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 deploys.
(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 attached 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 assembly 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 13 of 1202

- INTRODUCTIONFOR ALL OF VEHICLES
IN-13
13 Author: Date:
1996 TERCEL (RM440U)
(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 deployment of the supplemental re-
straint system.
(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 loosing the set
bolts of the airbag sensor assembly.
(g) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the instrument
panel wire harness assembly and floor wire harness as-
sembly. The wires for the SRS wire harness are encased
in a yellow corrugated tube. All the connectors for the sys-
tem are also a standard yellow color. If the SRS wire har-
ness becomes disconnected or the connector becomes
broken due to an accident, etc., repair or replace it as
shown on page RS-37.
Page 14 of 1202

IN-14
- INTRODUCTIONFOR ALL OF VEHICLES
14 Author: Date:
1996 TERCEL (RM440U)
2. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. 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.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
3. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two-way radios and cellular telephones, observe
the following precautions.
(1) Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the ve-
hicle's electronic systems. For details about ECU and sensors locations, refer to the section on
the applicable component.
(3) Avoid winding the antenna feeder together with other wiring as much as possible, and also avoid
running the antenna feeder parallel with other wire harnesses.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communications system.
4. FOR USING OBD II SCAN TOOL OR TOYOTA HAND-HELD TESTER
CAUTION:
Observe the following items for safety reasons:
Before using the OBD II scan tool or TOYOTA hand-held tester, the OBD II scan tool's instruc-
tion book or TOYOTA hand-held tester's operator manual should be read thoroughly.
Be sure to route all cables securely when driving with the OBD II 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 OBD II scan tool or TOYOTA hand-held
tester, one person to drive the vehicle and the other person to operate the OBD II scan tool or
TOYOTA hand-held tester.
Page 15 of 1202

IN07E-05
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-15
15 Author: Date:
1996 TERCEL (RM440U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the TERCEL. 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, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
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 accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI-1
2. Anti-Lock Brake SystemDI-109
3. Supplemental Restraint SystemDI-146
4. Power Door Lock Control SystemDI-190
5. Theft Deterrent SystemDI-215
Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.
If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or 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 outline in the Tester Operator's
Manual.
Page 16 of 1202

IN07F-06
Vehicle Brought to Workshop
Customer Problem
Analysis
Symptom Confirmation
and Diagnostic Trouble
Code Check
Symptom Simulation
Diagnostic Trouble
Code Chart
Problem Symptoms Table
Circuit Inspection or Parts
Inspection
Repair
Confirmation Test
End 1
2
43
5
6
7
8Ask the customer about the conditions and the
environment when the problem occurred.1
Confirm the symptoms and the problem conditions,
and check the diagnostic trouble codes.
(When the problem symptoms do not appear
during confirmation, use the symptom simulation
method described later on.)2, 3
Check the results obtained in Step 2, then confirm
the inspection procedure for the system or the part
which should be checked using the diagnostic
trouble code chart or the problem symptoms table.4, 5, 6
Check and repair the affected system or part in
accordance with the instructions in Step 6. 7
After completing repairs, confirm that the problem
has been eliminated.
(If the problem is not reproduced, perform the
confirmation test under the same conditions and
in the same environment as when it occurred for
the first time.)8
IN-16- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 TERCEL (RM440U)
HOW TO PROCEED WITH TROUBLESHOOTING
Carry out troubleshooting in accordance with the procedure on the following page. Here, only the basic pro-
cedure is shown. Details are provided in Diagnostics section, showing the most effective methods for each
circuit. Confirm the troubleshooting procedures first for the relevant circuit before beginning troubleshooting
of that circuit.