2001 TOYOTA AVALON Service Repair Manual

B02921
Example:
Correct
Wrong
Z13951
Example:
- INTRODUCTIONFOR ALL OF VEHICLES
IN-13
13 Author
: Date
:
2001 AVALON (RM808U)
(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 to 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 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-32).
Perform the operation in a safe place away from
electrical noise.

B02922
Example:
Correct
Wrong
N21642
Example:
IN-14
- INTRODUCTIONFOR ALL OF VEHICLES
14 Author
: Date
:
2001 AVALON (RM808U)
(f) SIDE AIRBAG ASSEMBLY
(1) Always store a removed or new side airbag assem-
bly 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 applied to the side airbag as-
sembly and the surface 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) under the
seat before starting work.
(6) When disposing of a vehicle or the side airbag as-
sembly alone, the airbag should be deployed using
an SST before disposal (See page RS-45).
Perform the operation in a safe place away from
electrical noise.

B02121
Example:
- INTRODUCTIONFOR ALL OF VEHICLES
IN-15
15 Author
: Date
:
2001 AVALON (RM808U)
(g) SEAT BELT PRETENSIONER
(1) Never measure the resistance of the seat belt pre-
tensioner. (This may cause the seat belt pretension-
er to activate, which is very dangerous.)
(2) Never disassemble the seat belt pretensioner.
(3) Never install the seat belt pretensioner in another
vehicle.
(4) Store the seat belt pretensioner where the ambient
temperature remains below 80°C (176°F) and
away from electrical noise without high humidity.
(5) When using electric welding, first disconnect the
connector (yellow color and 2 pins) before starting
work.
(6) When disposing of a vehicle or the seat belt preten-
sioner alone, the seat belt pretensioner should be
activated before disposal (See page BO-131). Per-
form the operation in a safe place away from electri-
cal noise.
(7) The seat belt pretensioner is hot after activation, so
let it cool down sufficiently before the disposal.
However never apply water to the seat belt preten-
sioner.

IN-16
- INTRODUCTIONFOR ALL OF VEHICLES
16 Author
: Date
:
2001 AVALON (RM808U)
(h) 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 loosing the set
bolts of the airbag sensor assembly.
(i) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the instrument
panel wire harness assembly. All the connectors in the
system are 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-82.

- INTRODUCTIONFOR ALL OF VEHICLES
IN-17
17 Author
: Date
:
2001 AVALON (RM808U)
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.

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IN-18
- INTRODUCTIONFOR ALL OF VEHICLES
18 Author
: Date
:
2001 AVALON (RM808U)
5. FOR VEHICLES EQUIPPED WITH TRACTION CON-
TROL (TRAC) & VEHICLE SKID CONTROL (VSC) SYS-
TEM
NOTICE:

When replacing the steering angle sensor or ECU, or
when adjusting the front wheel alignment or steering
wheel center point in accordance with the removing
and installing or replacing the suspension, axle, or
steering parts, make sure to perform the steering
angle sensor zero point calibration (See page
DI-252).

Do not remove or install the VSC related parts unless
necessary. Otherwise, there is a possibility that the
setting of the VSC to be affected.

When working on the VSC related operation, make
sure to check that the preparations before and after
work are completed according to the following
instruction.

When using a drum tester such as a speedometer tes-
ter or chassis dynamometer, etc., or jacking up the
front wheels and driving the wheels, always push in
the TRAC & VSC cut (ºVSC OFFº) switch and turn the
TRAC & VSC system OFF.
(a) Press the VSC OFF switch.
(b) Check that the VSC OFF indicator light comes ON.
HINT:
The VSC OFF indicator light should be always OFF when the
engine is restarted.
(c) Begin measurements.
(d) Press the VSC OFF switch again to change the TRAC &
VSC system to operational condition and check that the
VSC OFF indicator light goes off.
HINT:

The SLIP indicator light blinks when the TRAC system is
operational.

The SLIP indicator light blinks and the VSC buzzer
sounds when the VSC system is operational.

IN05Y-17
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-19
19 Author
: Date
:
2001 AVALON (RM808U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the AVALON. 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. Automatic TransaxleDI-158
3. Anti-Lock Brake System With Electronic Brake Force Distribution (EBD)DI-210
4. ABS With EBD & BA & TRAC & VSC SystemDI-250
5. Supplemental Restraint SystemDI-347
6. Power Seat Control System (w/ Driving position memory)DI-488
7. Theft Deterrent SystemDI-517
8. Cruise Control SystemDI-549
9. Engine Immobilizer SystemDI-597
10.Body Control SystemDI-615
11. Driver Door Control SystemDI-676
12.Passenger Door Control SystemDI-700
13.Multiplex Communication SystemDI-718
14.Air Conditioning SystemDI-752
FOR USING OBD II SCAN TOOL OR TOYOTA HAND-HELD TESTER

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 (Bus
line) 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.

IN05W-19
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-20- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
20 Author
: Date
:
2001 AVALON (RM808U)
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.