1991 MITSUBISHI 3000GT Service Manual

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - ~~~-~~~~~a~~g~~~s 52B-552. Repair Procedure
(1) If air bag deployed in the collision, remove the deployed
air bag module. (Refer to
P.52B-62.)(2) Check the SRS components using the table shown
below.
If the SRS components are showing any visible damage
such as dents, cracks, or deformation, replace them
with new ones.
Refer to appropriate INDIVIDUAL COMPONENT SER-
VICE, P.52B-56.
(3) Conduct self-diagnosis using Multi-use Tester to ensure
entire SRS operates properly except open circuit of air
bag module (22. SQUIB TRBL 2).
(4) Install new air bag module. (Refer to
P.52B-62.)
SRS ComponentsInspection(when air bag deploys in collision)Inspection (when air bag does not deploy
in low-speed collision)
Front impact sensors
Replace front impact sensors.(Refer to P.52B-56.)(1)Check front upper frame lower and sensor
brackets for deformities or rust.
(2)Check sensor cases for dents, cracks deformi-ties or rust.
(3)Check sensor harnesses for binds, connectors
for damage, and terminals for deformities.
SRS diagnosis unitSDU)Replace SRS diagnosis unit.(Refer to P.52B-59.)(1)Check SDU case and brackets for dents, cracksor deformities.(2)Check connectors and lock lever for damage,and terminals for deformities.
jir bag moduleReplace air bag module.(Refer to P.52B-62.)(1)Check pad cover for dents, cracks or deformi-ties.
(2)Remove air bag module from steering wheel.
Check hooks and connector for damage, termi-
nals for deformities, and harness for binds.
(Refer to P.52B-62.)(3)Check air bag inflator case for dents, cracks or
deformities.
(4)Install air bag module to steering wheel to.checlfit or alignment with the wheel.
Steering wheel/steering
(1)column/intermediateReplace steering wheel, steering
iointcolumn and intermediate joint.Remove air bag module from steering wheel.
(Refer to P.52B-62.)(Refer to GROUP 37A- Steering(2)Wheel and Shaft.)Check wiring harness (built into steering wheel)and connectors for damage, and terminals fordeformities.(3)Install air bag module to check fit or alignmentwith steering wheel.(4)Check steering wheel for noise, binds or
difficult operation and excessive free play,
Clock springReplace clock spring.(1)Check clock spring connectors and protective
tube for damage, and terminals for deformities.
(2)&/;yecheck the case and the gears for
Harness connectorIBody and Front wiring ’(1 )Check connectors for poor connections.
iarnessl(2)Check harnesses for binding, connectors for damage, and terminals for deformities.(Refer to P.52B-53 and P.52B-14.)
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52B-56SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - front lwtact sensors
INDIVIDUAL COMPONENT SERVICEIf the SRS components are to be removed or replaced as a result of maintenance, troubleshooting, etc.,
follow each procedure
(P.52B-56 - P.52B-68).L++(
Caution
1.SW components should not be subjected to heat over 93°C (2OO”F), so remove the front impactsensors, SRS diagnosis unit and air bag module and clock spring before drying or baking the
vehicle after painting. Recheck SRS system operability after re-installing them.
2.If the SRS components are removed for the purpose of check, sheet metal repair, painting, etc.,they should be stored in a clean, dry place until they are reinstalled.
FRONT IMPACT SENSORS
Caution1. Never repair or disassemble a front impact
sensor. If faulty, replace it.
2.Handle the front impact sensors very careful-
ly, taking care not to drop them or otherwise
subject them to impact. If a sensor is seen tobe dented, cracked, deformed or rusted,
replace it with a new one.
3.Replace sensors with new ones after the air
bag has deployed.
REMOVAL AND INSTALLATION
Removal steps
l *Post-installation inspectiona*1. Connection of the negative (-) battery
cable to the battery
2. Front splash shield extension
I)* 3. Front impact sensorI)*Pre-installation inspection
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Front impact Sensors52B-57Digital multi-meter
/
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SERVICE POINTS OF REMOVAL1. DISCONNECTION OF THE NEGATIVE
(-) BATTERY
CABLE FROM THE BATTERYTurn the ignition key to the “LOCK” position, disconnect
the negative battery cable and tape the terminal.
Caution
Wait at least 30 seconds after disconnecting the battery
cable before doing any further work. The SRS system is
designed to retain enough voltage to deploy the air bagfor a short time even after the battery has been
disconnected, so serious injury may result from unin-
tended air bag deployment if work is done on the SRSsystem immediately after the battery cable is discon-
nected.
INSPECTION
(I) Check upper frame and sensor brackets for deformities or
rust.
(2) Check sensor harness for binds, connectors for damage,
and terminals for deformities.
(3) Check for dents, cracks or deformation of the front impact
sensor.
Caution
If a dent, crack, deformation or rust is detected, replacewith a
.new sensor.
(4) Remove the front impact sensor.
(5) Measure the resistance between terminals and check
whether it is within the standard value.
Standard value: 2,000 + 40
iZ
CautionAlways replace the sensor with a new one if the
resistance is not within the standard value.
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52B-58SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Front Impact Sensors
SERVICE POINT OF INSTALLATION
PRE-INSTALLATION INSPECTION
(1) Before any front impact sensor is installed in the vehicle, it
must be visually inspected. If a dent, crack or other
LAdeformation, or rust, is detected, discard the sensor and
replace it with a new one that passes the visual inspection.
(2) Before any front impact sensor is installed in the vehicle,
the resistance between its terminals must be confirmed to
be within the standard value.
Standard value: 2,000
-t 400
Use the digital multi meter. If the resistance is not within
that standard value range, discard it and replace it with a
new one that has the standard value.
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INSTALLATI’ON OF FRONT IMPACT SENSOR
(1) Bend the wiring harness slightly (to the extent that
there is no slack), and clip securely by using the clip of
the front impact sensor.
(2) Install the front impact sensor so that there is close
adherence of the upper surface of the front impact
sensor and the installation surface of the upper frame
d’(lower).
Caution
The SRS may not activate properly if a front impact
sensor is not installed properly, which could result
Iin serious injury or death to the vehicle’s driver.
POST-INSTALLATION INSPECTIONReconnect the negative battery terminal. Turn the ignition
switch to “ON”. Does the
“SW” warning light illuminate for
about 7 seconds, turn OFF and then remain extinguished for at
least 45 seconds? If yes, SRS system is functioning properly. If
no, consult page 52B-17.
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)- SRS Diagnosis Unit (SDU) 52B-59
SRS DIAGNOSIS UNIT (SDU)M52PDBA
Caution1. Never attempt to disassemble or repair the
SRS diagnosis unit. If faulty, replace it.
2.Do not to drop or subject the SRS diagnosisunit to impact or vibration.
If denting, cracking, deformation, or rust are
discovered in the SRS diagnosis unit, replace
it with a new SRS diagnosis unit. Discard theold one.3. After deployment of an air bag, replace the
SRS diagnosis unit with a new one.
4.Never use an ohmmeter on or near the SRS
diagnosis unit, and use only the special testequipment described on
P.!i2B-16.
REMOVAL AND INSTALLATION
Removal steps
*aPost-installation inspectionaI)1. Connection of the negative
battery cable to the battery
2. Cup holder
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3. Console plug
4. Rear console assembly
a* l d5. Connection of the SRS diagnosis
unit and each harness connector
l *6. SRS diagnosis unit*cPre-installation inspection
2-pin yellow connector
to left front impact sensor
Z-pin red
tonneto clock sprrng
Z-pin dlueconnector
to right front
\Impact sensor14-pin red connector to body wlnng harness
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52B-60 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - SRS Diagnosis Unit (SW
0I/-Battery e
13R0721lSF1072:
SRS diagnosis unitView A13R0704
To front impact sensor
(L.H.)
\To front impact sensor (R.H.1\I
I- - -,I1
\To clock springTo body wiring harness (14-pin)19FOllt
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SERVICE POINTS OF REMOVAL1. DISCONNECTION OF THE NEGATIVE
(-) BATTERY
CABLE FROM THE BATTERYTurn the ignition key to the “LOCK” position, disconnect
the negative battery cable and tape the terminal.
Caution
Wait at least 30 seconds after disconnecting the battery
cable before doing any further work. The SRS system is
designed to retain enough voltage to deploy the air bagfor a short time even after the battery has been
disconnected, so serious injury may result from unin-
tended air bag deployment if work is done on the SRSsystem immediately after the battery cable is discon-
nected.5. DISCONNECTION OF THE SRS DIAGNOSIS UNIT AND
EACH HARNESS CONNECTOR(1) Use a screwdriver to push in the lock spring of the lock
lever of the SRS diagnosis unit to unlock the lock lever.
CautionA double-lock mechanism is employed for the
connector of the SRS diagnosis unit, so care mustbe taken not to damage the connector by using
excessive force or by not disconnecting it correctly.(2) Remove each connector from the SRS diagnosis unit
while pressing down the lock of each connector. (Refer
to
P.52B-9.)
INSPECTIONlCheck the SRS diagnosis unit case and brackets for dents,
cracks or deformities.
lCheck connectors and lock lever for damage, and terminals
for deformities.
CautionIf a dent, cracks, deformation or rust discovered,
replace the SRS diagnosis unit with a new one.
NOTEFor checking of the SRS diagnosis unit other than described
above, refer to the section concerning troubleshooting.
(Refer to
P.52B-17.)
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) -SRS Diagnosis Unit (SDU) 52B-611330721
13R072i
ht-----
SERVICE POINTS OF INSTALLATION
PRE-INSTALLATION INSPECTIONBefore SRS diagnosis unit is installed in the vehicle, it must be
visually inspected. If a dent, crack or other deformation is
detected, discard the SRS diagnosis unit and replace it with a
new one that passes the visual inspection.
6. INSTALLATION OF SRS DIAGNOSIS UNIT
With the projection part of the SRS diagnosis unit placed
against the bracket as shown in the figure, securely install
the SRS diagnosis unit.
CautionThe SRS may not activate properly if SRS diagnosis
unit is not installed properly, which could result in
serious injury or death to the vehicle’s driver.
5. CONNECTION OF THE SRS DIAGNOSIS UNIT AND
EACH HARNESS CONNECTORAfter connecting each harness connector securely and
correctly to the SRS diagnosis unit, be sure to press down
the lock lever of the SRS diagnosis unit.
POST INSTALLATION INSPECTION
Reconnect the negative battery terminal. Turn the ignition
switch to “ON”. Does the “SRS” warning light illuminate for
about 7 seconds, turn OFF and then remain extinguished for at
least 45 seconds? If yes, SRS system is functioning properly. If
no, consult page
52B-17.
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52B-62Air Bag ModuleSUPPLEMENTAL RESTRAINT SYSTEM (SRS) - and Clock Spring
AIR BAG MODULE AND CLOCK SPRINGM52PDCA
Caution1. Never attempt to disassemble or repair the
air bag module or clock spring.
If faulty, replace it.
2. Do not drop the air bag module or clock
spring or allow contact with water, grease or
oil.Replace it if a dent, crack, deformation or
rust are detected.
3.The air bag module should be stored on a flat
surface and placed so that the pad surface isfacing upward.
REMOVAL AND INSTALLATION1
l After setting the steering wheel antthe front wheels to the stralghtaheaposltion. remove the ignition key.5NmDo not place anything on top of it.
4.Do not expose the air bag module to temper-ILJ
ature over 93°C (200°F).
5After an air bag has deployed, replace with anew air bag module and check the SRS
operability.6. Wear gloves and safety glasses when han-
dling an air bag that has already deployed.
7. An undeployed air bag module should only
be disposed of in accordance with the proce-dures
[P.52B-69 - P.52B-721.
Air bag module removal stepsI)4
Post-installation inspection4*1. Connection of the negative (-1 battery
cable to the battery
*I) I)* 2. Air bag module3. Radio remote control assembly
4. Horn contact plate
5. Horn contact plate and wire
6. Horn button
7. Spring
l 4Pre-installation inspection
Clock spring removal steps
I)4Post-installation inspection4*1. Connection of the negative (-1 battery
cable to the battery
+* l +2. Air bag modulel * l a8. Steering wheelKnee protector 1(Refer to GROUP 52A-
Column coverJ Instrument Panel.)Floor console (Refer to GROUP 52A- FloorConsole.)
*I) *+9. Clock spring and SRS diagnosis unitconnection10. Clock spring and body wiring harness
connection
I)* 11. Clock springI)4Pre-installation inspection
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