warning light MITSUBISHI 3000GT 1991 Workshop Manual

52B-2SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - General informationGENERAL INFORMATION
INTRODUCTIONThe Supplemental Restraint System (SRS) is de-
signed to supplement the driver’s seat belt to help
reduce the risk or severity of injury to the driver by
activating and deploying a driver’s-side air bag in
certain frontal collisions.
The SRS consists of: left front and right front impact
sensors located, one each, on the right and left front
upper frame lowers; an air bag module located in
the center of the steering wheel, which contains the
folded air bag and an inflator unit; the SRS diagnosis
unit located under the rear console assembly, which
monitors the system, and which contains a safing
impact sensor; an SRS warning light located on the
instrument panel, which indicates the operational
status of the SRS; a clock spring interconnection
located within the steering column; system wiring
and wiring connectors; and a knee bolster located
SRS warning light
M52BAAFunder the steering column.
The SRS is designed so that the air bag will deploy
when the safing sensor, plus either or both of the
left front and right front impact sensors simul-
taneously activate while the ignition switches
“ON”.
That is designed to occur in frontal or near-frontal
impacts of moderate to severe force.
Only authorized service personnel should do work
on or around the SRS components. Those service
personnel should read this manual carefully before
starting any such work. Extreme care must be used
whenservicing the SRS, to avoid injury to the
service personnel (by inadvertent deployment of the
air bag) or the driver (by rendering the SRS inopera-
tive).
SELF-DIAGNOSIS/SRS WARNING LIGHT FUNCTION
The diagnosis unit monitors the SRS system and stores data
concerning any detected faults in the system. When the
ignition key is in “ON” or “START” position, the SRS warning
light should illuminate for about 7 seconds and then turn off.
That indicates that the SRS system is in operational order. If the
SRS warning light does any of the following, immediate
inspection by an authorized dealer is needed.
(1) The SRS warning light does not illuminate as described
above.
(2) The SRS warning light stays on for more than 7 seconds.
(3) The SRS warning light illuminates while driving.
If a vehicle’s SRS warning light is in any of these three
conditions when brought in for inspection, the SRS system
must be inspected, diagnosed and serviced
In accordance wrth
this manual.
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - General lnform=*ion52B-5
r1.c
L
E.
,
iiCAUTION: SRS diagnosis unit
This unit cannot be repaired.
If defective, remove and replace entire unit per
service manual instructions.
Do not disassemble or tamper.
See service manual for handling and storage
instructions.Driver’s air bag information
This vehicle
ha% an air bag which will supple-
ment the driver’s seatbelt in certain frontal
collisions. The air bag is not a substitute for the
driver’s seatbelt in any type of collision. The
driver, and all other occupants, should wear
seatbelts at all times.
WARNING!
If the “SRS” warning light does not come.on
for about 7 seconds when ignition key is turned
to “ON” or engine is started, or if it stays on
while driving, drive the vehicle to your nearest
authorized dealer right away. Also do so if
vehicle’s front end is damaged or if air bag has
deployed.
The air bag system must be inspected by an
authorized dealer ten years after vehicle manu-
facture date shown on certification label lo-
cated on left front door-latch post or door
frame.Read “SRS” section of your owner’s manual
before driving, for important information, about
Dperation, service and disposal of the air bag
svstem.
Do no drop: keep dry.
Failure to follow instructions could render air
bag inoperative and result in driver injury.
F. CAUTION: SRS
Before replacing steering wheel, read service
manual, center front wheels
ahd align SRS
clock spring neutral marks.
Failure to do so may render SRS system
inoperative, risking serious driver injury.
I.
J.WARNING: SRS
This air bag module cannot be repaired. Do not
disassemble or tamper.
Do not perform diagnosis. Do not touch with
electrical test equipment or probes. Refer to
service manual for further instructions, and for
special handling, storage and disposal proce-
dures.
Tampering or mishandling can result in injury.
Danger! Poison. Keep out of the reach of
children.
Contains sodium acid and potassium nitrate
contents are poisonous and extremely flamm-
able. Contact with acid, water, or heavy metals
may produce harmful and irritating gases or
explosive compounds. Do not dismantle, in-
cinerate or bring into contact with electricity or
store at temperatures exceeding
(93.3”C)
200°F.Fast aid: If contents are swallowed induce
vomiting. For eye contact flush eye with water
for 15 minutes. If gases from acid or water
contact are inhaled, seek fresh air. In every
case, get prompt medical attention.
For additional information, see material safety
data sheet (MSDS) for this product.
CAUTION: SRS clock spring
This is not a repairable part. Do not disassem-
ble or tamper.
If defective, remove and replace entire unit per
service manual instructions.
Before replacement, read service manual, cen-
ter front wheels and align neutral marks.
Failure to
foHow instructions may render SRS
system inoperative, risking serious driver in-
jury.CAUTION: SRS
Before removal of steering gearbox, read ser-
vice manual, center front wheels and remove
ignition key.
Failure to do so may damage SRS clock spring
and render SRS system inoperative, risking
serious driver injury.
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52B-6SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - General Information
;RS SCHEMATIC
STARTER RELAYIGNITION SWITCH MIT
I
‘dIGNITION SWITCH
IMulti
-purpose fuses
Connector
lock switch
----
r
1
UNLOCKiM/T -AA
IWarning light
malfunction
detection circuitICrank signal detection circuit
Connector lock
detection circuit
Safing
impact
sensor
1
N
i-Multi-use ,
Tester
interface
circuit
Self-diagnosis
check connector
(For Multi-use
Tester)
19FO141Front impact
sensor
(L.H.)Clock spring
Front impact
sensor (R.H.)IP-l-Air bag
module
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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - General information52B-11
SRS CIRCUIT DIAGRAM
IGNITION SWITCH(IG1)
I
I2B-W
COMBINATION METER
(SRS WARNING LIGHT)M,/T ! A(T
1.4w x 2iE
1047
?I!
-y 105
pq!g$g@-: l2
&S&7._----~~-_-~~_-_------~~~----- --- -_-_____-
7 T
%mY
1
I
WITHOUTTHEFT-ALfiF!M
INHIBITORSSWITCH-I
WITHTIiFm-0
II18IIIIIIIIIfIIIIIIIIIIIII
II
1 .I
I
LT\
MICROCOMPUTER
M/T
?-w
m
6
A/T
mI>a
SELF-DIAGNOSIS
CHECK CONNECTOR
V;ETF;)T1-USE*
:X35-AX-RlSOQ-N.._
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.52B-14 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - SRS Service Precautions
SRS SERVICE PRECAUTIONSMBZPBAA
1.In order to avoid injury to yourself or others from3.accidental deployment of the air bag during SRSNever Attempt to Repair the Following Com-servicing, read and carefully follow all the
pre-
ponents:dcautions and procedures described in this
manu-l Front Impact Sensors
al.l SRS Diagnosis Unit (SDU)
2.Do not use any electrical test equipment on orl Clock Spring
near SRS components, except those specifiedl Air Bag Module
on
P.52B-16.If any of those components are diagnosed as
Never use an analogue ohmmeter.faulty, they should only be replaced, in accord-
ance with the INDIVIDUAL COMPONENT SER-
VICE procedures in this manual, starting at page
[52B-561.
4.Do not attempt to repair the wiring harness connectors of the
SRS. If any of the connectors is diagnosed
as fault, replace the wiring harness. If the wires are diagnosed as faulty, replace or repair the wiring
harness according to the following table.
SDUTerminalNo.
Harness
Connector
(No. ofTerminals,Color)
101
102
2pins,red
51
52
2pins,yellow
12pins,
blue
2
II
II
I2 IIi
I3 I
4
t---i
14 pins,
5red
16 t
LDestination of Harness
Clock springReplace clock
spring.
Bodywiring
*
HarnessFront wiring
* HarnessFront impact+ sensor (LH)
Replace withsensor cable.*
Front wiring
--) HarnessFront impact* Sensor (RH)
--
-+ Diagnosis check pinCorrect or replace
-+ Control wiring harness+ Ignition switch (ST). control wiring,
instrument panel
-+ General purpose fuse No. 11wiring harness
or body wiringharness.+ General purpose fuse No. 18
Instrument panel+ wiring harnessSRS warning* light
-I-
~ JunctionBpdYCorrect or replace
block-+ wrnng-+ Groundharnessbody wiring harness.
NOTE(I)
(2)The sensor cable marked with * is available as service part.
The sensor cable used as a replacement part is routed along the body wiring harness.
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SRS ServicePrecautions /SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Spectiications52B-15View A
To front impact sensor
(L.H.)
\To frontimpactsensor (R.H.)
\To body wiring harness (14-pin)To clock spring19FOllOZ-pin blue connector to
right front impact sensor
Z-pin yellow connector
to left front impact sen2-pin red corm
to clock spring
SDU
14-pin red connector to body wiring harness
j.SRS components should not be subjected to heat over 93°C (2OO”F), so remove the front impact sensors,
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.
j. Whenever you finish servicing the SRS, check the SRS warning light operation to make sure that the
system function properly. (Refer to
P.52B-2.)
7. In case of any questions about the SRS, call the regional Tech Line at I-800-446-6064.
NOTESERIOUS INJURY CAN RESULT FROM UNINTENDED AIR BAG DEPLOYMENT, SO USE ONLY THE
PROCEDURES AND EQUIPMENT SPECIFIED IN THIS MANUAL.
SPECIFICATIONSMUCB-B
SERVICE SPECIFICATION
ItemsSpecification
Standard value
Front impact sensor resistanceQ2,000 f 40
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SUPPLEMENTAL RESfRAlNT SYSTEM (SRS) - Troub!eshooting 52B-17TROUBLESHOOTING
M52ECAA
idSRS DIAGNOSTIC PROCEDURES
- INITIAL STEPS’FOLLOW THESE STEPS WHEN BEGINNING ANY SRS SERVICE:
/II/ ,- -u’ 16FO304
SRS warning light
Multi-use fester
(MB991341)RbM pack(MB991359)
Diagnosis/
service data
output
Ground
16LOO9
[TSB
1. Check the SRS fuses (multi-purpose fuses No. 11 and No.
18).If either is loose, tighten it; if damaged or blown, replace it.
.
2.After performing step 1, start engine. Does “SRS” warning
light
illumi.nate for about 7 seconds and then turn OFF? If
yes, SRS system is functioning properly.
If no, continue with following steps.
NOTEIf the battery power supply (multi-purpose fuses No. 11 or
No. 18) is disconnected with the ignition key in the “ON”
position, the SRS warning light will continue to illuminate
even after the fuses are replaced in their original positions.
In this case, the SRS warning light can be extinguished by
turning the ignition switch ON and OFF
10 times.
3. Turn the ignition key to the “LOCK” position.
4. Insert ROM pack into the Multi-use Tester and connect
tester to Diagnosis Check Connector in glove compart-
ment.
5. Start the SRS diagnosis,by conducting TEST 1
(SRSwarninq liqht does not extinguish) or TEST 2 (SRS warning
light does- not illuminate.) which begins on next page or
page
[52B-191.
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52B-18 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
DIAGNOSTIC SEQUENCE
TEST 1SRS WARNING LIGHT DOES NOT EXTINGUISH
\1 I
Vehicle Model Selection
{
F
1. SELF-DIAG CODE2. SERVICE DATA
3. ACTUATOR TEST
4. SPECIAL TEST
,, I,
0
“CLEAR” and“4”1.
SIMLTD VEH SPD
2. PULSE CHK
3. DRIVE RECORDER4. EXTERNAL COMM
” 1 ”
1’1
y,,
SRS-AIR BAGID NO.: 19INPUTABOVE CODE
I(1) Turn the ignition key to the “ON” position.
(2) The Multi-use Tester display section successfully passes
the self-check and the model selection menu is displayed
after completing the self-check of the Multi-use Tester.
Select 3000GT 91 MDL [No. 3 (Non-Turbo) or No. 4 (Turbo)]
and SRS-AIR BAG system by entering the “YES” key.
(3) If the Multi-use Tester displays “CAN’T COMM.“, check
the Multi-use Tester and vehicle side self-check diagnosis
TSB Revisionconnector for poor connections (Refer to the previous
page.) and perform
[I.If the 3000GT 91 MDL SRS-AIR BAG system selection is
successful, continue with following steps.
(4) Select the “1. SELF-DIAG CODE” function and read (and
write down) all displayed diagnosis codes.
(5) Press the “CLEAR” key to return to the Function Selection
and select the
“4. SPECIAL TEST”.
(6) Pr+FE,the ”
1 ” key and select the “5. ERASE DIAG.
(7) Erase the diagnosis codes following the Multi-use Tester
messages.
(8) Start engine.
Does “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 now.
If no, check the diagnosis codes written down at step (4)
above, refer to SELF-DIAGNOSIS QUICK REFERENCE
CHART
(P.52B-20) and perform service indicated there.

SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting 52B-19
TEST 2SRS WARNING LIGHT DOES NOT ILLUMINATE
Vehicle Model Selection
-
pc-y-y
1. SELF-DIAG CODE
2. SERVICE DATA
3. ACTUATOR TEST
4. SPECIAL TEST
(1) Turn the ignition key to the “ON” position.
(2) The Multi-use Tester display section successfully passes
the self-check and the model selection menu is displayed
after completing the self-check of the Multi-use Tester,
select 3000GT 91 MDL [No. 3 (Non-Turbo) or No. 4 (Turbo)]
and SRS-AIR BAG system by entering the “YES” key.
(3) If the Multi-use Tester displays “CAN’T COMM.“, check
the Multi-use Tester and vehicle side self-check diagnosis
connector for poor connections (Refer to
P.52B-17.) and
perform
ITEST 4 1.If the 3000GT 91 MDL SRS-AIR BAG svstem selection is
successful, continue with following steps.
(4) Select the “1. SELF-DIAG CODE” function and read (and
write down) all displayed diagnosis codes.
(5) Check diagnosis codes against SELF-DIAGNOSIS QUICK
REFERENCE CHART and perform service indicated there.
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52B-20 SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - Troubleshooting
SELF-DIAGNOSIS QUICK REFERENCE CHART
Fault
No.
-
11
32
Diagnosis code name
[Failure mode]
(NORMAL)
G-SENS. TRBL
1[Short circuit]
G-SENS. TRBL 2[One open-circuit]
G-SENS. TRBL 3[Two open-circuit]
SQUIB TRBL 1[Short circuit]
SQUIB TRBL 2
[Open-circuit]
CONDENS. VO. HI
CONDENS. VO. LO
CRANKING TRBL
CONN. UNLOCKED
Explanation
Normal. The SRS is in goodorder.
The circuits for the front impact sensor are shortedto each other.
Right or left impact sensor cirucit is open or the
wire from the sensor to the SDU is open-circuit.
Right and left impact sensor circuits are open or thewires from the sensors to the SDU areopen-circuit.
The circuits for the air bag module (squib) are
shorted to each other or the circuit isgrounded.
The air bag module Isquib) circuit is open or the wire
from the air bag to the SDU (clock spring) is open-circuit.
The capacitor (integrated in the
SDU) terminal voltage
is higher than the specified value for 5 seconds.
The capacitor (integrated in the
SDU) terminal voltage
is lower than the specified value for 5 seconds.
The circuit for the cranking signal is shorted to
some power supply circuits.
It takes at least 45 seconds that the SDU detects
this fault.
The lock switch (short bar) of the SDU double lockconnector isopen.Service
Perform TEST 5
Perform TEST 6(I) Turn the ignition key
to the “LOCK” posi-
tion, disconnect the
negative battery
cable and tape the
terminal.
(2) After waiting atleast 30 seconds,
replace the SDU.
(Refer to P.52B-59.)
Perform TEST 7
Perform TEST 8NOTE
- 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
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