1991 MITSUBISHI 3000GT Service Manual

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-39
MB991349SRS Check Harness
connector
View ASRS Check Harness connector @
Ground
II No(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.
IIIIs there continuity between the No. 191 or No. 20 terminal ofi;RSCheck‘1 ~~~~~;,0~~~~~~.~~~-14.~r1 Ground ‘jrcuit Open1Harness connector @ and ground?
Reconnect negative terminal of
(()
terminal (of SRS Check Harness connec-
tor 0) and the No. 19 or 20 terminal(ground) indicate system voltage?NOTE
- IMPOR
TANT
Yes
(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, replacethe SDU.(Refer toP.52B-59.)
(1) Turn the ignition key
to the “LOCK” po-
sition, disconnect
the negative battery
cable and tape theterminal.
(2) After waiting at least
30 seconds, repair orreplace the body wir-ing harness. (Refer toP.52B-14.)
(1) If more than 45 seconds of cranking is required to start up the engine, the diagnosis code will be
stored in memory, but if there is no problem, the diagnosis code will be cleared and the SRS willreturn to normal.
(2) 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.)
(3) SDU
= SRS Diagnosis Unit
TSB Revision

52B-40 SUPPLEMENTAL ,RESTRAINT SYSTEM (SRS) - Troubleshooting
TEST 8REPAIR REQUIRED FOR “34. CONN. UNLOCKED” FAULT
SRS DIAGNOSIS UNIT-
r
--
L
FRONTSIDE
EESELF-DIAGNOSISCHECK CONNECTORLOCK SWITCH(FOR MULTI-USETESTER)KXB-AX-RIRW-YSRS diagnoskunit
13RQ7Q4View A
To front impact sensor
(L.H.)Todlock spring
I19F0110
To body wiring harness (14-pin)
(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 disconnectingthe battery cable before doing any further
work. The SRS system is designed to retainenough voltage to deploy the air bag for ashort 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 floor console. (Refer to GROUP
52A
- Floor Console.)
Is the SDU lock lever securely locked?~JII’~~
I11I
-1 Malfunction of the SDU> Replace the SDU.
(Refer to P.52B-59.1INOTE
- 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.)
(2) SDU
= SRS Diagnosis Unit
I
LA
I
I
I
J
TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-41
1 TEST 9 1 REPAIR REQUIRED FOR “41. IG VOLT LOW 1” FAULT1
i
IGNITIONJTCH;
DIIll
MLLTI -PURPOSE
SRS DIAGNOSIS UNITr----------------------------A
f------ ‘iSRS diagnoiis unit
View A
To front impact sensor
(L.H.)
\To front impact sensor (R.H.)To
klock spring\19FOllO
To body wiring harness (14-pin)
+a-
Lock I
“(2 0-Ji9FO103-I-I
(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.(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.)

52B-42 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
MB991349
SRS Check Harness
View ASRS Check Harness connector @
16R2188
Fuse’No. 18Ground
(5) Connect the now disconnected red harness-side SDUIconnector
(14-pin) to the connector @ of the SRS Check
Harness.
(6) Check according to the flow chart below, using the digital ‘&multi-meter.(
r, No
Is there continuity between the No. 19
or No. 20 terminal of SRS Check
Harness connector @ and ground?Ground circuit open
IYes
Reconnect negative terminal of
battery, and turn the ignition
key to the “ON” position.
the No. 19 or 20 terminal (ground) and
Yes
(1) Turn’the ignition key
to the “LOCK” po-
sition, disconnect
the negative battery
cable and tape theterminal.
(2) After waiting at least
30 seconds, repair orreplace the body wir-ing harness. (Refer tcP.52B-14.)
I
I
Malfunction of the SDU> (I) Turn the ignition keyto 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 the”~
Multi-use Tester and check the SRS warning light operation to verify the system functions
L/1properly. (Refer to TEST 1.)
(2) SDU
= SRS Diagnosis Unit
TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-43
1 TEST 10 1 REPAIR REQUIRED FOR “42. IG VOLT LOW 2” FAULT1
,
IGNITION SWITCH(IG1)I
MILT I -PURPOSE
SRS DIAGNOSIS UNIT_~_----_-__--_--_-__---~--~~SRS diagnosis unit
13R0704
View ATo front impact sensor
(L.H.)
\ ,To front impact sensor (R.H.)To dlockspring
/lSFO110
To body wiring harness (14-pin)
(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.(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.)

52B-44 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
MB991349SRS Check Harness(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.d
View ASRS Check Harness connector @t- Fuse No. 11
Ground
/, NoIs there continuity between the No. 19or No. 20 terminal of SRS Checki- Ground circuit open1
Harness connector @ and ground?i
I
Yes
Reconnect negative terminal of
( py;;;;fgJ;p ~~y~~on>
- NoIs there a voltage of 9V or more be-> Damaged or disconnected wir-tween the No. 19 or 20 terminal (ground)
and the No. 11 terminal of the SRSing of fuse No. 11, or damaged
Check Harness connector
@?or disconnected body wiringharness.
Yes
(1) Turn the ignition keyto the.“LOCK” po-
sition, disconnect
the negative battery
cable and tape the
terminal.
(2) After waiting at least30 seconds, repair orreplace the body wir-ing harness. (Refer toP.52B-14.)
) Malfunction of the SDU> (1) Turn the ignition keyto 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.)
1 TSB RevisionINOTE
- IMPORTANT
(1) After repairing the SRS, reconnect the battery cable, erase the diagnosis code memory from the’Multi-use Tester and check the SRS warning light operation to verify the system functions
\iproperly. (Refer to TEST 1.)
d(2)
SDU = SRS Diagnosis Unit

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-45
TEST 11REPAIR REQUIRED FOR “43. SRS LMP TRBL 1” FAULT
(SRS warning light does not extinguish)
IGNITION SWITCH(IG1)
COMBINATION METER(SRS WARNING LIGHT)1.4w x 2
r _________ - ____..__-----SRS DIAGNOSIS UN11I" n
/ 1 -1 "fT%~~ION CIRCUIT/
SELF-DIAGNOISISCHECK CONNECTOR(TFEOSRTOF.h~ll-USE=Kx35-Ax-RIY)I-I
SRS diagno&unit13R0704
View ATo front impact sensor (L.H.)
\To front impact sensor (R.H.1
To’clock spring\19FOllO
To body wiring harness (14-pin)
< lever
I 7’1,~,JLockspring ( lonnector notch-
2
(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-
netted .(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 the red
16pin connector from the SRS diagno-
sis unit while pressing down the lock of the connector.
(Refer to
P.52B-9.)
TSB Revision

52B-46 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
(5) Reconnect negative terminal of battery, and turn the
ignition key to the “ON” position.
(6) Check according to the flow chart below.
- NoDoes the SRS warning light remainilluminated when the red 14-pinconnector of the SDU is disconnected?
) Malfunction of the SDU) (I) Turn the ignition key
to the “LOCK” po-sition, disconnect
Yesthe negative batterycable and tape the
terminal.
(2) After waiting at least30 seconds, replace
the SDU. (Refer to
P.52B-59.)
A--NOTE
- IMPORTANT(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, repair orreplace the body wir-ing harness. (Referto P.52B-14.)
I
dl
i i
(1) After repairing the SW, 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
TSB Revision