TOYOTA T100 1996 Factory Service Manual

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SRS AIRBAG RS-1
STEERING WHEEL PAD AND SPIRAL
CABLE RS-7
AIRBAG SENSOR ASSEMBLY RS-21
FRONT AIRBAG SENSOR RS-26
WIRE HARNESS AND CONNECTOR RS-31

Downloaded from www.Manualslib.com manuals search engine RS03H−01
− SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS−1
1768 Author: Date:
1996 TOYOTA T100 (RM449U)
SRS AIRBAG
PRECAUTION
NOTICE:
The TOYOTA T100 is equipped with SRS, which comprises a driver 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 required. Before performing servicing
(including removal or installation of parts, inspection or replacement), be sure to read the fol-
lowing items carefully, then follow the correct procedures described in the repair manual.
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, air-
bag sensor assembly and front airbag sensor should be inspected (See page RS−9, RS−23 and
RS−28).
Never use SRS parts from another vehicle. When replacing parts, replace them with new parts.
Never disassemble and repair the steering wheel pad, airbag sensor assembly or front airbag
sensor in order to reuse it.
If the steering wheel pad, airbag sensor assembly or front airbag sensor has been dropped, or
if there are cracks, dents or other defects in the case, bracket or connector, replace them with
new ones.
Use a volt/ohmmeter with high impedance ( 10 kΩ/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 or SRS side airbag
warning light check (See page DI−365).
If the vehicle is equipped with a mobile communication system, refer to the precaution in the
IN section.
CAUTION:
Work must be started after 90 seconds from when the ignition switch is turned to the ”LOCK”
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.)
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.
Before repairs, remove the airbag sensor if shocks are likely to be applied to the sensor during
repairs.
Do not expose the steering wheel pad, airbag sensor assembly or front airbag sensor directly
to hot air or flames.

Downloaded from www.Manualslib.com manuals search engine RS03I−03
R07746
AB0250Spiral Cable
Z09709
w/ Tachometer:
w/o Tachometer:
R12497
RS−2
− SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
1996 TOYOTA T100 (RM449U)
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 generant, 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. SRS WARNING LIGHT
The SRS warning light is located on the combination meter. It
goes on to alert the driver of trouble in the system when a mal-
function is detected in the airbag sensor assembly. 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.
4. AIRBAG SENSOR ASSEMBLY
The airbag sensor assembly is mounted on the floor inside the
lower center cover. The airbag sensor assembly consists of an
airbag sensor, safing sensor, diagnosis circuit, ignition control,
drive and circuit, etc.
It receives signals from the airbag sensor and judges whether
the SRS must be activated or not.

Downloaded from www.Manualslib.com manuals search engine R08038
H03005
Connector 1Connector 2
No.1 J/B
Connector 3
Spiral CableConnector 4
Squib
Rh and LH Front
Airbag Sensor
Connector 5 Center Airbag
Sensor Assembly
Z05953
Spacer
Housing
Female Male
− SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS−3
1996 TOYOTA T100 (RM449U)
5. FRONT AIRBAG SENSOR
The front airbag sensor is mounted inside each of the front
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 sensor cannot be disassembled.
6. SRS CONNECTORS
No.ItemApplication
(1)Terminal Twin−Lock MechanismConnectors 2, 3, 4
(2)Airbag Activation Prevention MechanismConnectors 1, 3, 4
(3)Electrical Connection Check MechanismConnectors 1, 5
(4)Connector Twin−Lock MechanismConnectors 3, 4
(a) All connectors in the SRS are colored yellow to distin-
guish them from other connectors. Connectors having
special functions and specifically designed for the SRS
are used in the locations shown above to ensure high reli-
ability. These connectors use durable gold−plated termi-
nals.
(1) Terminal Twin−Lock Mechanism
Each connector has a two−piece component con-
sisting of a housing and a spacer. This design se-
cures the locking of the terminal by two locking de-
vices (the retainer and the lance) to prevent
terminals from coming out.

Downloaded from www.Manualslib.com manuals search engine R10587
When Connector is Connected When Connector is Disconnected
Short Spring Plate
Housing
Housing
Terminal
ConnectorsShort Spring PlateSquib
Closed CircuitSquib Short Spring Plate ONContacting Male Terminal Short Spring Plate
RS−4
− SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
1996 TOYOTA T100 (RM449U)
(2) Airbag Activation Prevention Mechanism
Each connector contains a short spring plate. When
the connector is disconnected, the short spring
plate automatically connects the power source and
grounding terminals of the squib.
HINT:
The illustration on the previous page shows connectors ”3” and
”4”.

Downloaded from www.Manualslib.com manuals search engine R07799
Connection
Detection
Pin
Resistor
Front Airbag Sensor
R10586
Connection Detection Pin
Terminal for Diagnosis
SlopeConnection Detection
Pin Contacting Terminal Half Connection
Complete Connection
Z05490
Secondary Lock
Ribs
Primary Lock
LockLock
Primary Lock Incomplete
(Secondary Lock Prevented)Primary Lock Complete
(Secondary Lock Permitted)Twin−Lock Completed
− SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
RS−5
1996 TOYOTA T100 (RM449U)
(3) Electrical Connection Check Mechanism
This mechanism electrically checks if 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.
(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.

Downloaded from www.Manualslib.com manuals search engine Z14845
Safing SensorFig.1
Power Source
Fig.2
Squib
Front
Airbag
Sensor Center
Airbag
Sensor RS−6
− SUPPLEMENTAL RESTRAINT SYSTEMSRS AIRBAG
1996 TOYOTA T100 (RM449U)
(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 airbag sensor go
on simultaneously. When deceleration force acts on the
sensors, squib in the driver airbag ignite and generate
gas. The gas discharging into the driver airbag rapidly in-
creases the pressure inside the bags, breaking open the
steering wheel pad.
Bag inflation then ends, and the bags deflate as the gas
is discharged through discharge holes at the bag’s rear or
side.

Downloaded from www.Manualslib.com manuals search engine RS03J−01
Z14844
Under Column Cover
Steering Wheel Pad
No.3 Cover No.2 Cover
Torx Screw
Combination Switch
Lower Column CoverLower Finish Panel No.1
− SUPPLEMENTAL RESTRAINT SYSTEMSTEERING WHEEL PAD AND SPIRAL CABLE
RS−7
1774 Author: Date:
1996 TOYOTA T100 (RM449U)
STEERING WHEEL PAD AND SPIRAL CABLE
COMPONENTS

Downloaded from www.Manualslib.com manuals search engine RS03K−01
RS−8
− SUPPLEMENTAL RESTRAINT SYSTEMSTEERING WHEEL PAD AND SPIRAL CABLE
1996 TOYOTA T100 (RM449U)
REMOVAL
(See page SR−13 or SR−33)

Downloaded from www.Manualslib.com manuals search engine RS03L−02
R07746
R06972
R05736
Horn Button Contact Plate
− SUPPLEMENTAL RESTRAINT SYSTEMSTEERING WHEEL PAD AND SPIRAL CABLE
RS−9
1996 TOYOTA T100 (RM449U)
INSPECTION
1. VEHICLES NOT INVOLVED IN A COLLISION
(a) Do a diagnostic system check.
(See page DI−365)
(b) Do a visual check which includes the following items with
the steering wheel pad (with airbag) installed in the ve-
hicle.
Check for cuts, minute cracks or marked discoloration on
the steering wheel pad top surface and in the grooved
portion.
2. VEHICLE INVOLVED IN A COLLISION AND AIRBAG IS
NOT DEPLOYED
(a) Do a diagnostic system check.
(See page DI−365)
(b) Do a visual check which includes the following items with
the steering wheel pad (with airbag) removed from the ve-
hicle.
Check for cuts, minute cracks or marked discolor-
ation on the steering wheel pad top surface and in
the grooved portion.
Check for cuts and cracks in wire harness, and chip-
ping in connectors.
Check for the deformation of the horn button con-
tact plate of the steering wheel.
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.