ignition MITSUBISHI 3000GT 1991 Service Manual

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
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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.)
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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

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.)
iB RevisionI

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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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Front impact Sensors52B-57Digital multi-meter
/
19FOlC
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.
1 TSB RevisionI

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.
19FOO6i4.
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.
19FOO72
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