Page 1720 of 1943

RS0JO±06
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS±1
1600 Author: Date:
2001 PRIUS (RM778U)
SRS AIRBAG
PRECAUTION
CAUTION:
The PRIUS 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. Further, if a
mistake is made in servicing the SRS, it is possible that the SRS may fail to operate when re-
quired. Before performing servicing (including removal or installation of parts, inspection or
replacement), be sure to read the following items carefully, then follow the correct procedures
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±14, RS±28, RS±41, RS±53, RS±58 and RS±63)
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±497).
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. To avoid erasing the memory in each memory system, never
use a back± up power supply from outside the vehicle.
If the vehicle is equipped with a mobile communication system, refer to the precaution in the
IN section.
Page 1721 of 1943

RS0R8±01
H15220
R09725Spiral Cable
H15507
H15678
H15676
RS±2
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2001 PRIUS (RM778U)
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.
Page 1723 of 1943
H15711
Airbag
Sensor
AssemblySide Airbag Sensor
Assembly (RH)
Side Airbag
Assembly (RH) (Squib)
Seat Belt
Pretensioner (RH)
Front Airbag Sensor (RH)
Front Passenger Airbag
Assembly (Squib)
Steering Wheel
Pad (Squib)
Front Airbag Sensor (LH)
Side Airbag
Assembly (LH) (Squib) Seat belt
Pretensioner (LH) 10 7
8
9
11
6
5
1213
4
14
15
16
2
1
3
Spiral Cable
Side Airbag Sensor
Assembly (LH) RS±4
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2001 PRIUS (RM778U)
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, 16
(2)Airbag Activation Prevention MechanismConnectors 1, 2, 3, 4, 5, 6, 8, 9, 14, 15
(3)Electrical Connection Check MechanismConnectors 1, 2, 3
Page 1726 of 1943

Z14034
Fig.1
Fig.2Power Source
Safing
Sensor
Squibs
Deceleration Sensor
H01581
Outer
H01582
Lock of connector is released
Disconnection is completed
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS±7
2001 PRIUS (RM778U)
(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.
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.
Page 1729 of 1943
H01586
Slider
Disconnection is completed Slider
RS±10
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
2001 PRIUS (RM778U)
(a) Align a lock part of male connector and a slider of female
connector in the same direction as shown in the illustra-
tion, fit in them without rubbing.
(b) 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.)
HINT:
As the slider slides, do not touch it.
Be careful not to deform the release board. If the release
board is deformed, replace it with a new one.
15. DISCONNECTION OF CONNECTORS FOR STEERING
WHEEL PAD (with AIRBAG) AND FRONT PAS-
SENGER AIRBAG ASSEMBLY
(a) Place a finger on the slider.
(b) Slide the slider to release lock.
(c) Disconnect the connector.
Page 1730 of 1943
H01587
Slider
Slider
± SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS±11
2001 PRIUS (RM778U)
16. CONNECTION OF CONNECTORS FOR STEERING
WHEEL PAD (with AIRBAG) AND FRONT PAS-
SENGER AIRBAG ASSEMBLY
(a) Align a lock part of male connector and a slider of female
connector in the same direction as shown in the illustra-
tion, fit in them without rubbing.
(b) 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.)
HINT:
As the slider slides, do not touch it.
Be careful not to deform the release board. If the release
board is deformed, replace it with a new one.
Page 1731 of 1943

RS0JS±07
H15220
H16239
H16240
Horn Button
Contact Plate
H15220
RS±14
± SUPPLEMENTAL RESTRAINT SYSTEMSTEERING WHEEL PAD AND SPIRAL CABLE
2001 PRIUS (RM778U)
INSPECTION
1. Vehicle not involved in collision:
INSPECT SUPPLEMENTAL RESTRAINT SYSTEM
(a) Do a diagnostic system check (See page DI±497).
(b) Do a visual check which includes the following item with
the steering wheel pad (with airbag) installed in the ve-
hicle.
Check cuts, minute cracks or marked discoloration on the
steering wheel pad top surface and in the grooved por-
tion.
2. Vehicle involved in collision and airbag is not
deployed:
INSPECT SUPPLEMENTAL RESTRAINT SYSTEM
(a) Do a diagnostic system check (See page DI±497).
(b) Do a visual check which includes the following items with
the steering wheel pad (with airbag) removed from the ve-
hicle.
Check cuts, minute cracks or marked discoloration
on the steering wheel pad top surface and in the
grooved portion.
Check cuts and cracks in wire harness, and chip-
ping in connectors.
Check the deformation of the horn button contact
plate of the steering wheel.
CAUTION:
For removal and installation of the steering wheel pad, see
page SR±6 and SR±14, be sure to follow the correct proce-
dure.
HINT:
If the horn button contact plate of the steering wheel is de-
formed, never repair it. Always replace the steering wheel
assembly with a new one.
There should be no interference between the steering
wheel pad and steering wheel, and the clearance should
be uniform all the way around when the new steering
wheel pad is installed on the steering wheel.
Page 1732 of 1943

H16240
Horn Button
Contact Plate
H15220
± SUPPLEMENTAL RESTRAINT SYSTEMSTEERING WHEEL PAD AND SPIRAL CABLE
RS±15
2001 PRIUS (RM778U)
3. Vehicle involved in collision and airbag is deployed:
INSPECT SUPPLEMENTAL RESTRAINT SYSTEM
(a) Do a diagnostic system check (See page DI±497).
(b) Do a visual check which includes the following items with
the steering wheel pad (with airbag) removed from the ve-
hicle.
Check the deformation on the horn button contact
plate of the steering wheel.
Check the damage on the spiral cable connector
and wire harness.
CAUTION:
For removal and installation of the steering wheel pad, see
page SR±6 and SR±14, and be sure to follow the correct
procedure.
HINT:
If the horn button contact plate of the steering wheel is de-
formed, never repair it. Always replace the steering wheel
assembly with a new one.
There should be no interference between the steering
wheel pad and steering wheel, and the clearance should
be uniform all the way around when the new steering
wheel pad is installed on the steering wheel.