1991 MITSUBISHI 3000GT sensor

52B-22 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
TEST 3NO COMMUNICATION BETWEEN MULTI-USE TESTER AND SDU
(SRS warning light does not extinguish)
COMBINATION METER(SRS WARNING LIGHT)
SRS DIPGNOSIS UNITSRS
diag(osis unit
View A13R0704To front impact sensor
(L.H.)
\To front impact sensor (R.H.)To
clock springI19FOllO
To body wiring harness (14-pin)
13R072113RO72:L
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
IQpin connector from the SRS diagno- Q’sis unit while pressing down the lock of the connector.
(Refer to
P.52B-9.)
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(1) Turn 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 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.
Caution
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52B-24 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
TEST 4NO COMMUNICATION BETWEEN MULTI-USE TESTER AND SDU
(SRS warning light does not illuminate)
IGNITION SWITCH(IG1)
J/.8(MULTI -PURPOSEFUSES)
SRS DIAGNOSIS UNIT
MULTI -3SETESTER1
KKRS-AX-RISE+R
View ASRS diagnbsis unit
To front impact sensor
(L.H.)
\To front impact sensor (R.H.)Toclock spring
I19FOllO
To body wiring harness (14-pin)
onnectornotch -UNLOCKED
;;bb;;,LOCKED zRok
(1) Turn 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 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.
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.
idi
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i(4) Disconnect the red l4-pin connector from the SRS diagno- L/~
sis unit while pressing down the lock of the connector.
(Refer to
P.52B-9.)
\
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52B-26 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
TEST 5REPAIR REQUIRED FOR "11. G-SENS. TRBL I”, “12. G-SENS. TRBL 2” or
“13. G-SENS. TRBL 3” FAULT
SRS DIAGNOSIS UN1
IMPACT S!NSOR~M&N"E DETECTION
FRONT IMPACTSENS0RtL.H.)FRONT IMPACTsEN80R(R. H. )--u-~,w-*
Front impact sensor resistance checkDigital multi-meter
r ~1iii”~“‘.,,,,/ ?\I. I,// q
NOTEIf combined front impact sensor and air bag module (squib) failure modes simultaneously occur in two places,
the preconditions for the respective detection circuits will go out of order. For this reason, both diagnosis
codes may not be stored but only one of them may be indicated.
Their relationships are shown in the following table.
Front impact sensors
Air bag module
(Squib)Short-circuitedOpen-circuitedShort-circuited
11 and/or 21
11 and/or 22One open-circuitedTwo open-circuited12 and/or 2113 and/or 21I12 and/or 2213 and/or 22
I
The numbers in the boxes are diagnosis codes numbers. (Refer to P.52B-20.)
/SRS diagnosis unit
View A
13u070rTo frontimDact sensor
(L.H.)
ITo clock springI19FOllO
To body wiring harness (14-pin)
lQFO102
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 529-27
MB991 349
SRS Check HarnessFront impact
sensor con-
nectar (R.H.)@ (blue)
View ASRS Check Harness connector @
Left
Right
16R2189
(I) Turn 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 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.
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 each connector other than
14-pin connector
from the SRS diagnosis unit while pressing down the lock
of each connector. (Refer to
P.52B-9.)(5) Locate the blue and yellow connectors for the wiring
leading to the front impact sensors, which were connected
to the now-disconnected harness-side connector of the
SDU. Connect those blue and yellow connectors to
connector @ of the SRS Check Harness.
(6) Check according to the flow chart below, using the digital
multi-meter and Multi-use Tester.
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529-28 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - TroubleshootingI
I NoIs the resistance between the No. 3 Is the resistance between the No. 3terminal of SRS Check Harness connec- terminal of SRS Check Harness connec-
tor @ and the No. 4 terminal normal? tor @ and the No. 4 terminal normal?Standard value: 2,000 k 400Standard value: 2,000 k 400
Yes
the terminals of the leftfront impact sensor normal?(Refer to P.526-26.)Standard value:2,000 k 40R
Yes
i
Front wiring harness is
grounded or open.
IIJ
?No -Is the resistance between the No. 5) Is the resistance between-Noterminal of SRS Check Harness connec-tor @ and the No. 6 terminal normal?the terminals of the right
Standard value: 2,000 2 4Oflfront impact sensor normal?(Refer to P.52B-26.)Standard value:Yes2,000 t 40R
Yes
Front wiring harness is
grounded or open.
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CONTINUED ON NEXT PAGENOTE
- IMPORTANT
(1) After repairing the SRS, reconnect the battery cable, erase the diagnosis code memory from thedMulti-use Tester and check the SRS warning light operation to verify the system functions
properly. (Refer to TEST 1.)
(2) SDU
= SRS Diagnosis Unit
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LSUPPLEMENTAL RESTRAINT SYSTEM (SRS)
- Troub!eshooting 529-29
/ CONTINUED FROM PREVIOUS PAGE/*
(1)Connect the red 2-pin connector @ of the SRS CheckHarness to the SDU in place of the now-disconnected clock spring-SDU connector.
NOTEA 3-ohm resistor that corresponds to the resistance
of the air bag module (squib) and the wiring resis-
tance is connected between the terminals of the
connector
@ of the SRS Check Harness.
(2)Reconnect blue.and yellow connectors, for the wiring
leading to the front impact sensors, to the SDU anddouble lock them. (Refer to
P.52B-9.)
NOTEIf double locking cannot be made, the connector isincorrectly or incompletely inserted; re-check to
insert the connector correctly and securely.
”
CONTINUED ON NEXT PAGEIMB991 349
SRS Check Harness
SRS CheckHarness
\ ii%\19FOO93NOTE
- IMPORTANT
(I) 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.)
(2) SDU
= SRS Diagnosis Unit
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-33
1 TEST 6 )REPAIR REQUIRED FOR “21. SQUIB TRBL 1” or “22. SQUIB TRBL 2” FAULT1
i
FRONTSIDE
Ez
IGNITION SWITCH(IG1)CautionNever attempt to measure the circuit resistance of
the air bag module
(squib) even if you are using thespecified tester. If the circuit resistance is measuredwith a tester, accidental air bag deployment will
result in serious personal injury.
SRS DIAGNOSIS UNIT
------I
SELF-DIAGNOISISCHECK CONNECTOR(FOR MULTI-USETESTER)ms!+Ax-Pls95-Y
J/B
AIR (BSAgGU#DULEView A
SRS diagnosisunit
13uo704
To front impact sensor (L.H.1
\To front impact sensor (R.H.)
Todock springI19FOllOTo body wiring harness (IQpin)
No
Have the other diagnosis code test(s)/> Perform the other diagnosis
been finished?code test(s) prior to this test.
/I
Yes
NOTE
If combined front impact sensor and air bag module (squib) failure modes simultaneously
occur in two places, the preconditions for the respective detection circuits will go out of
order. For this reason, both diagnosis codes may not be stored but only one of them may
be indicated.Their relationships are shown in the following table.
Front impact sensors
Short-circuited One open-circuited Two open-circuited
Air bagShort-circuited11 and/or 2112 and/or 2113 and/or 21
module(Squib)Open-circuited11 and/or .2212 and/or 2213 and/or 22
The numbers in the boxes are diagnosis codes numbers. (Refer to P.52B-20.)
LICONTINUED ON NEXT PAGE
1 TSB Revision

52B-38 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
TEST 7REPAIR REQUIRED FOR “33. CRANKING TRBL” FAULT1
STARTERHULAYIGNITIONSWITCH(ST>
7%INHIBITOR
10SWITCH
FI
pkEE&r -...__ -_-_-___I4SRS DIAGNOSIS UNITI
I---..-___________ - ____
2
14 13
!z
CLYL
da d4--__J/S
-A) @g
:6x36-NC-R1606-USRS diagnosis unit
13R0704View A
To front impact sensor (L.H.)
\To frontimpactsensor (R.H.)
II19FOllOTo clock spring
To body wiring harness (14-pin)
(I) Turn 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 assembly. (Refer to GROUP 52A-.
13R07211310722
- 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 not
to damage the connector by using excessive force or bynot disconnecting it correctly.
(4) Remove the red
14-pin connector from the SRS diagnosis
unit while pressing down the lock of the connector. (Refer
to
P52B-9.1
I/’
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