sensor LEXUS SC400 1991 Service Manual Online

Wire Harness and Connector
HINT: The wires for the airbag wire harness are encased in a yellow corrugate\
d tube and all the connectors in
the system are a standard yellow color.
INSPECTION ITEMS
1. VEHICLES NOT INVOLVED IN A COLLISIONw Perform a diagnostic system check (See page AB±30).
2. VEHICLES INVOLVED IN A COLLISION (a) Perform a diagnostic system check (See page AB±30).
(b) If there is a break in any of the wires in the airbag system wire harness,\
or if conductors are exposed.
(c) If the airbag system wire harness connectors are cracked or chipped.
REPLACEMENT REQUIREMENTS
In the following cases, replace the wire harness or connector.
w If any part of the airbag system wire harness or any connector has been fo\
und to be faulty in trouble-
shooting.
w If any part of the airbag system wire harness or any connector has been \
found to be faulty during the
check in item 2±(b) or (c).
NOTICE: If the wire harness used in the airbag system is damaged, replace the w\
hole wire harness
assembly.
When the connector to the airbag front sensors can be repaired alone (when \
there is no damage
to the wire harness), use the repair wire specially designed for the pu\
rpose (See page AB±20).
AB±12
SRS AIRBAG
± Inspection Items and Replacement Requirements
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PREPARATION
SST (SPECIAL SERVICE TOOLS)
09082±00700SRS Airbag
Deployment Tool
09213±31021Crankshaft Pulley
Puller
09843±18020Diagnosis Check
Wiring
Steering wheel
RECOMMENDED TOOLS
09042±00010Torx Socket
T30
09042±00020Torx Socket
T30
09082±00015TOYOTA
Electrical Tester
Center airbag sensor assembly
Steering wheel pad
EQUIPMENT
Part NameNote
Torque wrench
AB±13SRS AIRBAG ± Preparation
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Front Airbag Sensor
Remove and install the parts as shown.
(MAIN POINTS OF REMOVAL AND
INSTALLATION)
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the LOCK position and the negative (±) terminal
cable is disconnected from the battery (See page AB±2).
NOTICE:
wIf the wiring connector of the airbag system is discon-
nected with the ignition switch at ON or ACC, diagnostic
codes will be recorded.
wNever use airbag parts from another vehicle. When
replacing parts, replace with new parts.
wNever reuse the sensor involved in a collision when the
airbag has deployed.
wNever repair a sensor in order to reuse it.
AB±16SRS AIRBAG ± Removal and Installation of Component Parts
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INSTALL FRONT AIRBAG SENSOR
Install the sensor with the arrow on the sensor facing toward
the front of the vehicle.
Torque: 25 NVm (260 kgf Vcm, 19 ft Vlbf)
NOTICE:
wMake sure the sensor is installed to the specified torque.
wIf the sensor has been dropped, or there are cracks, dents
or other defects in the case, bracket or connector, replace
the sensor with a new one.
wThe sensor set bolts have been anti±rust treated. When
the sensor is removed, always replace the set bolts with
new ones.
wAfter installation, shake the sensor to check that there is
no looseness.
wThe front sensor is equipped with an electrical
connection check mechanism. Be sure to lock this
mechanism securely when connecting the connector. If
the connector is not securely locked, a malfunction code
will be detected by the diagnosis system.
wCheck that the dimensions of the body where the front
airbag sensor is installed match those in the body
dimension drawings on page BO±133.
(The airbag may malfunction, or may not work, if the
mounting angle or dimensions of the sensor mount
are not correct.) AB±17
SRS AIRBAG
± Removal and Installation of Component Parts
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Center Airbag Sensor Assembly
Remove and install the parts as shown.
AB±18SRS AIRBAG ± Removal and Installation of Component Parts
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(MAIN POINTS OF REMOVAL AND
INSTALLATION)
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the LOCK position and the negative (±) terminal
cable is disconnected from the battery (See page AB±2).
NOTICE:
wDo not open the cover or the case of the ECU and various
computers unless absolutely necessary. (If the IC termi-
nals are touched, the IC may be destroyed by static elec-
tricity.)
wNever use airbag parts from another vehicle. When
replacing parts, replace with new parts.
wNever reuse the center airbag sensor assembly involved
in a collision when the airbag has deployed.
wNever repair a sensor in order to reuse it.
REMOVE AND INSTALL CENTER
AIRBAG SENSOR ASSEMBLY
(a) Using a torx wrench, loosen and tighten the three screws.
Torx wrench: T40 (Part No. 09042±00020 or locally manufac-
tured tool)
Torque: 13 N Vm (130 kgf Vcm, 9 ft Vlbf)
NOTICE:
wMake sure the sensor assembly is installed to the speci-
fied torque.
wIf the sensor assembly has been dropped, or there are
cracks, dents or other defects in the case, bracket or
connector, replace the sensor assembly with a new one.
wWhen installing the sensor assembly, take care that the
airbag wiring does not interfere with other parts and is
not pinched between other parts.
wAfter installation, shake the sensor assembly to check
that there is no looseness.
(b) Disconnect the connector. AB±19
SRS AIRBAG
± Removal and Installation of Component Parts
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REPLACEMENT OF REPAIR WIRE
FOR FRONT AIRBAG SENSOR
Repair wire with two pressure±contact sleeves (Part No.
82988±50010) has been prepared for exclusive use in repairing
connector damage etc. caused by frontal collision of the vehicle.
When repairing the front airbag sensor connector on the wire har-
ness side, always use the special repair wire.
NOTICE: Do not replace the connector housing or terminal
only.
REPLACEMENT OF AIRBAG REPAIR
WIRE
CAUTION: Work must be started after approx. 20
seconds or longer from the time the ignition switch is
turned to the ªLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
1. DISCONNECT WIRE HARNESS AT VEHICLE SIDE (a) Remove the cover at the rear of the connector housingand expose the wire harness.
(b) Cut the wire harness behind the connector housing.
HINT: The operation is performed more easily if the wire har-
ness is left as long as possible.
2. CONNECT FRONT AIRBAG SENSOR WIRE HARNESS AT
VEHICLE SIDE AND REPAIR WIRE
(a) Start s tripping at least 8 mm (0.31 in.) to 11 mm (0.43 in.)
away from the end of the existing harness at vehicle side
and also from the end of the repair wire.
NOTICE: Take care not to damage the wire when strip-
ping the wire harness lead. After finishing the operation,
visually inspect the wire. If there is any damage, perform
the operation again.
(b) O ve rla p th e two stri pped wire ends inside of the
pressure±contact sleeve as illustrated in the left.
HINT: The blue pressure±contact sleeve (Part No.
AB±20
SRS AIRBAG
± Replacement of Repair Wire for Front Airbag Sensor
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HINT: You might find it easier if you use a miniature screwdriv-
er as a guide as you insert wires into the sleeve.
(c) The crimping tool (AMP Part No. 169060) has colormarks on it. Place the sleeve in the correct section of the
tool according to the color of the sleeve itself.
HINT: As the crimping tool, AMP ªPart No. 169060º is conve-
nient to use.
(d) With the center of the sleeve correctly placed between the crimping jaws, squeeze the crimping tool until either
end comes into contact at the section marked by
ªCLOSE HEREº.
HINT: Check to see that the sleeve and wires are still in
the correct position before closing the crimping tool
ends with steady pressure.
(e) Pull the joined wires to either end. Make sure that they
are jointed firmly by the sleeve.
NOTICE: If the jointed wires come loose the splice is de-
fective, so replace the sleeve and repeat the procedure.
(f) Crimp both ends of the sleeve with the crimping tool at the ªINSº position. AB±21
SRS AIRBAG
± Replacement of Repair Wire for Front Airbag Sensor
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3. PROTECT JOINED SECTIONWrap silicon tape around the joins to protect them from water.
HINT:
wBefore starting the operation, thoroughly wipe dirt and
grease off the sections to be joined.
wIf the adhesive surfaces of two tapes come in contact
they will stick together and will not come apart, so do not
remove the backing film except when using the tape.
wDo not let oil and dust, etc. get on the tape surface.
(a) Ready about 100 mm (3.94 in.) of silicon tape (Part No.
08231±00045) and peel off the film.
(b) Stretch the silicon tape until its width is reduced by half.
(c) About 10 mm (0.39 in.) from the end of the pressure±contact sleeve, wrap the silicon tape around
the sleeve three or more times while stretching the tape.
(d) Wrap the remaining part of sleeve with half of the tape overlapping at each turn.
(e) Firmly wrap the tape two times or more about 10 mm (0.39 in.) from the other end of the pressure±contact
sleeve, then wrap the tape back towards the start again
and firmly finish winding the tape around the center of
the sleeve.
(f) Fix the corrugated tube to the cabtire cable using silicon tape.
(g) After applying the silicon tape, apply vinyl tape on the corrugated tube of repair wire side over to the
corrugated tube of vehicle wire harness side.
AB±22
SRS AIRBAG
± Replacement of Repair Wire for Front Airbag Sensor
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Description
The SRS (Supplemental Restraint System) airbag, together with
the seat belt, is designed to help protect the driver. In a collision,
the airbag sensors detect the shock, and if the front±to±rear shock
is greater than a specified value, an airbag stored in the steering
wheel pad is inflated instantaneously to help reduce the shock to
the driver.
LOCATION OF COMPONENTS
AB±24SRS AIRBAG ± Troubleshooting
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