1991 MITSUBISHI 3000GT Service Manual

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-47
TEST 12REPAIR REQUIRED FOR “43. SRS LMP TRBL 1” FAULT(SRS warning light does not illuminate)
M'LTI-PUROSE
1
COMEIINATION METER(SRS WARNING LIGHT)1.4w x 205
SRS DIAGNOSIS UNI'
piw&pg ‘---pm
‘=lam-Ax-9150,-Y
SRS diagnosis unit
13R0704
View ATo front impact sensor
(L.H.)
\ ITo front impact sensor (R.H.)
T
Odlock spring
I19FOH0
To body wiring harness (14-pin)
(1)
IikPl s-a7 Lock leverTurn 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.
(2) Remove the rear console assemblv. (Refer to GROUP 52A
- Floor Console.)
(3) Use a screwdriver to push in the lock spring of the lock
lever of the SRS diagnosis unit to unlock the lock lever.
Caution
A double-lock mechanism is employed for the connec-
tor of the SRS diagnosis unit, so care must be taken notto damage it by using excessive force or by not
disconnecting it correctly.
-(4) Disconnect the red 14-pin connector from the SRS diagno-
sis unit while pressing down the lock of the connector.
(Refer to
P.52B-9.)
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52B-48 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
MB991 349
SRS Check Harness
14-pin SDUconnector(red)
View ASRS Check Harness connector @
SRS
warning lightGround(5) Connect the now disconnected red harness-side SDU
connector
(14-pin) to the connector @ of the SRS Check
Harness.(6) Check according to the flow chart below, using the digital
’multi-meter.drI No
IIs there continuity between the No. 19or No. 20 terminal of SRS Check!--Ground circuit open
Harness connector
@ and ground?Yes
Reconnect negative terminal of
(()
No. 19 or 20 terminal (ground) and the
the SIX Check Harness connector @?Yes
)/ Malfunction of the SDU-1
(1) Turn the ignition key
to the “LOCK” po-
sition, disconnect
the negative battery
cable and tape the
terminal.
(2) After waiting at least30 seconds, replace
the bulbs, repair or
replace the body wir-
ing harness.(Refer toP.52B-14.)
(I ) Turn the ignition key
to the “LOCK” po-
sition, disconnect
the negative battery
cable and tape the
terminal.
(2) After waiting at least30 seconds, replace
the SDU. (Refer to
P.52B-59.)NOTE
- IMPORTANT
(1) After repairing the SRS, reconnect the battery cable, erase the diagnosis code memory from theMulti-use Tester and check the SRS warning light operation to verify the system functions
properly. (Refer to TEST 1.)
d(2) SDU
= SRS Diagnosis Unit
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Z~-%Z%&Z% 528-49Manufacture
date
IVEHICLE TYPE: PASSENGER CAR
MU9001/
OOFOOOlSRS
warnmq light- -SDU’
t>19FOlO:SRS MAINTENANCE AND
POST-COLLISION DIAGNOSIS
M52PCAAMAINTENANCE
The SRS must be inspected by an authorized dealer
10 years
after the car manufacture date shown on the certification label
located on left front door latch post.
Maintenance Items
1.“SRS” WARNING LIGHT CHECK
When the ignition key is turned to “ON” or engine started,
the “SRS” warning light will illuminate for about 7 seconds
and then turn off.
This means that the system is functioning properly.
2. SRS COMPONENTS VISUAL CHECK
(1) Turn the ignition key to the “LOCK” position, discon-
nect the negative battery cable and tape the terminal.
CautionWait at least 30 seconds after disconnecting the
battery cable before doing any further work. The
SRS system is designed to retain enough voltage todeploy the air bag for a short time even after the
battery has been disconnected, so serious injury
may result from unintended air bag deployment
if
work is done on the SRS system immediately afterthe battery cable is disconnected.
(2) Remove the rear console assembly. (Refer to GROUP
52A
- Floor Console.)
(3) 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 must
be taken not to damage it by using excessive forceor by not disconnecting it correctly.
(4) Disconnect the red
14-pin connector from the SRS
diagnosis unit while pressing down the lock of the
connector. (Refer to
P.52B-9.)
13R0721113R0722
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52B-50 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - k%-%%,na~~g::i!isFrontupper frame lower
19FOO67
2-1 Front Impact Sensors
(1) Remove right and left front splash shield extensions.
Check sensors to ensure the arrow marks face the front
of the vehicle.
(2) Check front upper frame lowers and sensor brackets for
deformities or rust.
Caution
The SRS may not activate properly if a front impact
sensor is not installed properly, which could resultin serious injury or death to the vehicles driver.
(3) Check wiring harness (for front impact sensor) for
binds, connector for damage, and terminals for deformi-
ties.
Replace sensor and/or wiring harness if it fails visual
check. (Refer to
P.52B-56 and P.52B-14.)SRS Diagnosis Unit (SDU) 2-2
(11 Check SDU case and brackets for dents, cracks,
deformities or rust.
Caution
The SRS may not activate properly if SRS diagnosis
unit is not installed properly, which could result inserious injury or death to the vehicle’s driver.
(2) Check connectors and lock lever for damage, and
terminals for deformities or rust.
Replace SDU if it fails visual check. (Refer to
P.52B-59.)
LL
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SRS Maintenance and
SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Post-coltision Diagnosis 52B-51
2-3 Air Bag Module, Steering Wheel and Clock Spring
Rtng gearRotor
Screw
3at ca
To remote controlswitchAir bag module
Remote control
switch (radio)
To body wiring harness
SRS diagnosisunit
19FO150
19FO119(1) Remove air bag module from steering wheel. (Refer to
P.52B-62.)
CautionWhen disconnecting the air bag module-clock spring
connector, take care not to apply excessive force to it.(2) Check pad cover for dents, cracks or deformities.
CautionThe removed air bag module should be stored in a
clean, dry place with the pad cover face up.
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52B-52 SUPPLEMENTAL RESTRAINT SYSTEM fSRSI - ~Z-%~~~~aK&%kTo air bagmodule
To SRS dragnosls unit
I19FOO89(3) Check hooks and connectors for damage, terminals defor-
mities, and harness for binds.
(4) Check air bag inflator case for dents, cracks or deformities.
\(5) Check harness (built into steering wheel) and connectors
~for damage, and terminals for deformities.LA
(6) Remove the steering wheel by using a steering wheel
puller.
CautionDo not hammer on the steering wheel. Doing so may
damage the collapsible column mechanism.
(7) Remove the steering column covers. (Refer to GROUP 52A
- Instrument Panel.)
(8) Remove the clock spring. (Refer to
P.52B-62.)
(9) Check clock spring connectors and protective tube for
damage, and terminals for deformities.
(10)Visually check the clock spring case and the gears for
damage.(1 l)Align the mating mark and “NEUTRAL” position indicator
and, after turning the vehicle’s front wheels to straight-
ahead position, install the clock spring to the column
switch.
CautionIf the clock spring’s mating mark is not properly
aligned, the steering wheel may not be completely
rotational during a turn, or the flat cable within the
clock spring may be severed, obstructing normal
operation of the SRS and possibly leading to serious
injury to the vehicle’s driver.
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SRS Maintenance and
SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Post-collision Diagnosis 52B-53
2-4Front Wiring Harness and Body Wiring Harness
(12)lnstall the steering wheel, steering column covers and the
air bag module.
(13)Check steering wheel for noise, binds or difficult operation.
(14)Check steering wheel for excessive free play.
REPLACE ANY VISUALLY INSPECTED PART IF IT FAILS THAT
INSPECTION.(Refer to
P.52B-62.)
CautionThe SRS may not activate properly if any of the above
components is not installed properly, which could result inserious injury or death to the vehicle’s driver.
36FOO19(1) Check connectors for poor connections.
(2) Check harnesses for binds, connectors for damage, and
terminals for deformities.
REPLACE ANY CONNECTORS OR HARNESS THAT FAIL THE
VISUAL INSPECTION.
(Refer to
P.52B-14.)
CautionThe SRS may not activate properly if SRS harnesses or
connectors are damaged or improperly connected, whichcould result in serious injury or death to the vehicle’s
driver.
i
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52B-54 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - ZZ%K%~g~~~s
POST-COLLISION DIAGNOSISTEST EQUIPMENT TO BE USED FOR POST-COLLISION DIAGNOSIS
ToolNumberName
Use
MB991 341Multi-use tester subassemblyl Reading diagnosis codesl Reading trouble periodl Erasing diagnosis codel Reading erase times
MB991 359
ROM pack (for Multi-
use Tester
Multi-usejesterR'OM pack(MB991341)(MB991 359)
Diagnosis/
service data
output
I
16LOO9'Function Selection
Data ListTo inspect and service the SRS after a collision (whether or not
the air bag has deployed), perform the following steps.
1. SRS Diagnosis Unit Memory Check
(1) Insert ROM pack into the Multi-use Tester and connect
the tester to Diagnosis Check Connector in glove
compartment.
‘I i(2) Read (and write down) all displayed diagnosis codes.J’(Refer to
P.52B-18.)
NOTEIf the battery power supply has been disconnected or
disrupted by the collision, the Multi-use Tester cannot
communicate with the SRS diagnosis unit. Inspect and,
if necessary, repair the body wiring harness before
proceeding further.
(3) Select the “2. SERVICE DATA” function and read (and
write down) all displayed “91. TRBL PERIOD” (Fault
duration) and “92. ERASE TIMES” (how many times
memories are erased.). Refer to Multi-use Tester
Instruction Manual (MB991 342).
NOTEl Maximum stored period: 9999 minutes (approx-
imately 7 days)
l Maximum number of times to be stored: 250
(4) Erase the diagnosis codes and after waiting 45 seconds
‘dor more read (and write down) all displayed diagnosis
codes. (Refer to P.528-18.)
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