sensor TOYOTA AVALON 2001 Service Repair Manual

H11878
RS0EF-02
R09725Spiral Cable
H11879
H11880
H11881
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS-3
1523 Author
: Date
:
2001 AVALON (RM808U)
OPERATION
1. STEERING WHEEL PAD (with AIRBAG)
The inflater and bag of the SRS are stored in the steering wheel
pad and cannot be disassembled. The inflater contains a squib,
igniter charge, gas generator, etc., and inflates the bag when
instructed by the airbag sensor assembly.
2. SPIRAL CABLE (in COMBINATION SWITCH)
A spiral cable is used as an electrical joint from the vehicle body
side to the steering wheel.
3. FRONT PASSENGER AIRBAG ASSEMBLY
The inflater and bag of the SRS are stored in the front passen-
ger airbag assembly and cannot be disassembled. The inflater
contains a squib, igniter charge, gas generator, etc., and in-
flates the bag when instructed by the airbag sensor assembly.
4. SIDE AIRBAG ASSEMBLY
The inflater and bag of the SRS side airbag are stored in the
side airbag assembly and cannot be disassembled. The inflater
contains a squib, igniter charge, gas generator, etc., and in-
flates the bag when instructed by the side airbag sensor assem-
bly.
5. SEAT BELT PRETENSIONER
The seat belt pretensioner system is a component of the front
seat outer belt. The pretensioner contains a squib, gas genera-
tor, wire, piston, etc., and operates in the event of a frontal colli-
sion. The seat belt pretensioner cannot be disassembled.

H11969
H11882
Floor Shift:
Column Shift:
H11883
H11884
RS-4
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
1524 Author
: Date
:
2001 AVALON (RM808U)
6. SRS WARNING LIGHT
The SRS warning light is located on the accessory meter. It
goes on to alert the driver of trouble in the system when a mal-
function is detected in the airbag sensor assembly self-diagno-
sis. In normal operation conditions when the ignition switch is
turned to the ACC or ON position, the light goes on for about 6
seconds and then goes off.
7. AIRBAG SENSOR ASSEMBLY
The airbag sensor assembly is mounted on the floor inside the
lower center finish panel. The airbag sensor assembly consists
of an airbag sensor, safing sensor, diagnosis circuit, ignition
control, drive circuit, etc. It receives signals from the airbag sen-
sor, front airbag sensor, side airbag sensor assembly and door
side airbag assembly and judges whether the SRS must be ac-
tivated or not. The airbag sensor assembly cannot be disas-
sembled.
8. FRONT AIRBAG SENSOR
The front airbag sensor is mounted inside each of the side
members. The sensor unit is a mechanical type. When the sen-
sor detects deceleration force above a predetermined limit,
contact is made in the sensor, sending a signal to the airbag
sensor assembly. The front airbag sensor cannot be disas-
sembled.
9. SIDE AIRBAG SENSOR ASSEMBLY
The side airbag sensor assembly is mounted in the LH and RH
center pillars. The side airbag sensor assembly consists of a lat-
eral deceleration sensor, safing sensor, diagnosis circuit, etc.
It sends signals to the airbag sensor assembly to judge whether
the SRS side airbag must be activated or not. The side airbag
sensor assembly cannot be disassembled.

H11971
Airbag Sensor
Assembly12
3
8
9
10
Side Airbag Assembly (RH)
(Squib)
11
12
13
14
Seat Belt Pretensioner (RH)
Side Airbag Sensor
Assembly (RH)
Front Airbag Sensor (RH)
5
Front Passenger Airbag
Assembly (Squib)
Spiral Cable7
Steering Wheel
Pad (Squib) 6
15
Front Airbag Sensor (LH)
Side Airbag Sensor
Assembly (LH)
Seat Belt Pretensioner (LH)
Side Airbag Assembly (LH)
(Squib) 4
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS-5
1525 Author
: Date
:
2001 AVALON (RM808U)
10. SRS CONNECTORS
HINT:
SRS connectors are located as shown in the following illustra-
tion.
No.ItemApplication
(1)Terminal Twin-Lock MechanismConnectors 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
(2)Airbag Activation Prevention MechanismConnectors 1, 2, 3, 4, 5, 6, 7, 15
(3)Electrical Connection Check MechanismConnectors 1, 2, 3
(4)Connector Twin-Lock MechanismConnectors 5

R12076Airbag Sensor AssemblyDisconnection
Detection
PinSRS
Warning
Light
H01315
Terminal for Diagnosis
Disconnection Detection Pin
Half Connection
Complete Connection
Terminal for
Diagnosis
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS-7
1527 Author
: Date
:
2001 AVALON (RM808U)
HINT:
The type of connector is shown in the diagram on the previous
page.
(3) Electrical Connection Check Mechanism
This mechanism electrically checks that connectors
are connected correctly and completely. The electri-
cal connection check mechanism is designed so
that the disconnection detection pin connects with
the diagnosis terminals when the connector hous-
ing lock is locked.
HINT:
The illustration shows connectors º1º, º2º and º3º in step 10.

AB0089
Secondary Lock
Primary LockLockLock
Primary Lock Incomplete
(Secondary Lock Prevented)Primary Lock Complete
(Secondary Lock Permitted)Twin-Lock Completed
Z14034
Fig.1
Fig.2Power Source
Safing
Sensor
Squibs
Deceleration Sensor RS-8
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
1528 Author
: Date
:
2001 AVALON (RM808U)
(4) Connector Twin-Lock Mechanism
With this mechanism connectors (male and female
connectors) are locked by 2 locking devices to in-
crease the connection reliability. If the primary lock
is incomplete, ribs interfere and prevent the sec-
ondary lock.
(b) When the vehicle is involved in a frontal collision in the
hatched area (Fig. 1) and the shock is larger than the pre-
determined level, the SRS is activated automatically. A
safing sensor is designed to go on at a smaller decelera-
tion rate than the airbag sensor. As illustrated in Fig. 2,
ignition is caused when current flows to the squib, which
happens when a safing sensor and the deceleration sen-
sor go on simultaneously. When a deceleration force acts
on the sensors, 2 squibs in the driver airbag and front pas-
senger airbag ignite and generate gas. The gas discharg-
ing into the driver airbag and front passenger airbag rap-
idly increases the pressure inside the bags, breaking
open the steering wheel pad and instrument panel.
Bag inflation then ends, and the bags deflate as the gas
is discharged through discharge holes at the bag's rear or
side.

H01581
Outer
H01582
Lock of connector is released
Disconnection is completed
H01583
Outer
Outer
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS-9
1529 Author
: Date
:
2001 AVALON (RM808U)
11. DISCONNECTION OF CONNECTORS FOR FRONT
AIRBAG SENSOR AND SIDE AIRBAG SENSOR
(a) While holding both flank sides of the outer, slide the outer
to the direction shown by an arrow.
(b) Lock of the connectors is released, then disconnect the
connectors.
HINT:
Be sure to hold both flank sides of the outer. If holding the top
and bottom sides, it will obstruct disconnection.
12. CONNECTION OF CONNECTORS FOR FRONT AIR-
BAG SENSOR AND SIDE AIRBAG SENSOR
(a) Align the male connector (of the side of sensor) and fe-
male connector in the same direction as shown in the il-
lustration and fit in them without rubbing.
(b) As they are fitted in, the outer slides rearward. Press it un-
til the outer returns to its original position again.
If fitting stops half way, connectors will separate.
(c) Be sure to insert until they are locked. After fitting in, pull
them slightly to check that they are locked (When locked,
make sure that the outer returns to its original position and
sound at the time of fitting in can be heard.).

RS01Y-34
- SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS-1
1521 Author
: Date
:
2001 AVALON (RM808U)
SRS AIRBAG
PRECAUTION
CAUTION:

The AVALON is equipped with SRS, which comprises a driver airbag, front passenger airbag
and side airbag. Failure to carry out service operations in the correct sequence could cause
the SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Fur-
ther, if a mistake is made in servicing the SRS, it is possible that the SRS may fail to operate
when required. Before performing servicing (including removal or installation of parts, inspec-
tion or replacement), be sure to read the following items carefully, then follow the correct proce-
dures described in the repair manual.

Work must be started 90 seconds after 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
from disconnecting the negative (-) terminal cable of the battery, the SRS may be deployed.)

Do not expose the steering wheel pad, front passenger airbag assembly, side airbag assembly,
airbag sensor assembly, front airbag sensor or side airbag sensor assembly directly to hot air
or flames.
NOTICE:

Malfunction symptoms of the SRS are difficult to confirm, so the DTCs become the most impor-
tant source of information when troubleshooting. When troubleshooting the SRS, always in-
spect the DTCs before disconnecting the battery.

Even in cases of a minor collision where the SRS does not deploy, the steering wheel pad, front
passenger airbag assembly, side airbag assembly, airbag sensor assembly, front airbag sen-
sor and side airbag sensor assembly should be inspected.
(See page RS-15, RS-30, RS-44, RS-57, RS-64, RS-69, RS-74 and RS-79)

Before repairs, remove the airbag sensor if shocks are likely to be applied to the sensor during
repairs.

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

Never disassemble and repair the steering wheel pad, front passenger airbag assembly, side
airbag assembly, airbag sensor assembly, front airbag sensor or side airbag sensor assembly
in order to reuse it.

If the steering wheel pad, front passenger airbag assembly, side airbag assembly, airbag sen-
sor assembly, front airbag sensor or side airbag sensor assembly has been dropped, or if there
are cracks, dents or other defects in the case, bracket or connector, replace it with new one.

Use a volt/ohmmeter with high impedance (10 kW/V minimum) for troubleshooting the system's
electrical circuits.

Information labels are attached to the periphery of the SRS components. Follow the instruc-
tions on the notices.

After work on the SRS is completed, perform the SRS warning light check (See page DI-349).

When the negative (-) terminal cable is disconnected from the battery, the memory of the clock
and audio system will be canceled. So before starting work, make a record of the contents mem-
orized in the audio memory system. When work is finished, reset the audio systems as they
were before and adjust the clock. This vehicle has power seat which are all equipped with
memory function. However, it is not possible to make a record of the memory contents. So when
the work is finished, it will be necessary to explain this fact to the customer, and ask the custom-
er to adjust the features and reset the memory. To avoid erasing the memory in each memory
system, never use a back- up power supply from outside the vehicle.

RS06H-10
H11972
Spiral Cable Accessory Meter
(Warning Light)Front Passenger Airbag Assembly
Side Airbag Assembly (RH)
Side Airbag Sensor
Assembly (RH)
Seat Belt Pretensioner (RH) Side Airbag Sensor
Assembly (LH)
Seat Belt
Pretensioner (LH)
Side Airbag Assembly (LH)Airbag Sensor Assembly Front Airbag Sensor (RH)
Steering Wheel Pad
(with Airbag)Front Airbag
Sensor (LH)
RS-82
- SUPPLEMENTAL RESTRAINT SYSTEMWIRE HARNESS AND CONNECTOR
1602 Author
: Date
:
2001 AVALON (RM808U)
WIRE HARNESS AND CONNECTOR
LOCATION

- STEERINGPOWER STEERING GEAR
SR-57
1520 Author
: Date
:
2001 AVALON (RM808U)
12. CHECK STEERING WHEEL CENTER POINT
13. TORQUE STEERING WHEEL SET NUT
Torque: 50 N´m (510 kgf´cm, 37 ft´lbf)
14. INSTALL STEERING WHEEL PAD (See page SR-22)
15. CHECK FRONT WHEEL ALIGNMENT
(See page SA-4)
16. w/ VSC:
PERFORM STEERING ANGLE SENSOR ZERO POINT
CALIBRATION (See page DI-252)

SR0EH-06
F08837
Floor shift:
8.8 (90, 78 in.´lbf)
50 (510, 37)
Torx ScrewSteering Wheel Pad
Steering Wheel Lower
No. 2 Cover
Combination Switch
(w/ Spiral cable)
Column Upper Cover
Column Lower CoverSteering Wheel Lower
No. 2 CoverSteering Wheel
Steering Column
Assembly
Clamp
Intermediate Shaft
Sub-assembly
25 (260, 19)
N´m (kgf´cm, ft´lbf): Specified torqueTorx Screw
Lower Instrument Finish
Panel Assembly
Return Spring
No. 2 Column Hole
Cover Sub-assemblyUniversal Joint Assembly No. 2 Column Lower CoverSteering Angle
Sensor
Lower No. 1 Instrument
Panel Sub-assembly
Lower LH Instrument Panel
Insert Sub-assembly
No. 2 Heater to Register Duct
Air Cleaner Assembly
with Air Cleaner Hose
Steering Angle
Sensor Adapter Speed Control Main
Switch Assemblyw/ VSC:
w/ VSC:
8.8 (90, 78 in.´lbf)
35 (360, 26)
35 (360, 26)
35 (360, 26)
Hood Lock Release Lever
- STEERINGTILT STEERING COLUMN
SR-9
1472
2001 AVALON (RM808U)
TILT STEERING COLUMN
COMPONENTS