1991 MITSUBISHI 3000GT sensor

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 information52B-3
ONSTRUCTION DIAGRAM
Right front Impact sensor
/Left front impact
sensor
SRS diagnosis
unit(Incorporated safing
impact sensor)19FO138‘EHICLE
1~ENTIFICATION:ODE CHART
‘LATEmodulelQFO118
NOTEThis construction diagram displays the general view of the SRS components.
For details, refer to “SRS Schematic”
(P.52B-6). “Configuration Diagrams” (P.52B-7) and “SRS Circuit Diagram”(P.52B-11).
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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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52B-8SUPPLEMENTAL RESTRAINT SYSTEM (SRS) - General Information
36FOOOlJ/C-57 Clock spring
C-59 Ignition switch
C-79 Self-diagnosis check
connector (For
Multi-use Tester)
IbJInstrument panel and floor console
D-
D-03
D-04Combination meter
D-05
D-2314-pin red connector
to body wiring harness
D-24Z-pin blue connector to
right front impact sensor
D-252-pin yellow connector to
left front impact sensor
D-262-pin red connector to
clock springConnector to
SRS Diagnosis
UnitD-26225
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52B-12SUPPLEMENTAL RESTRAINT SYSTEM (SRS) -General Information
CAUTION1.DO not repair, splice or modify SRS wiring (except for specific repairs to the body wiring harness shown on page QB-14
2.replace wiring if necessary, after reading and following all precautions and procedures in this manual.DO not use an analogue ohmmeter to check SRS wiring or components; use only special tools and digital multi-metershown on page 52B-16.
12B-W2B-W
,, 7
B-WI\.J/B0(MULTI-PURPOSEFUSES)
10A
0.85B-WI' 2
---_-__--_----_--------~---~~~--~~--~~-~-~----~---- --_5SRS DIAGNOSIS UNIT
= CONSTANT4I- -xI
> VOLTAGE CIRCUITCONDENSIDETECTIL,. vAI\vvII ,
vvvn ,n N~,11rrnm,vn
Ttttlr .,,,,,,a
l@i fTii51 l@!l %piJ’
/
-i----
EBI
102!x 101
‘o’ @ii?r
i 1I
z
dd
3) clEl $1BVIi2VI
Qy y2 qli y jl y2/
FRONTIMPACTFRONT ' - ' '
SENSOR
I!?--
IMPACT
SENSOR
(L.H.)OFF -If-(R. H. )II
CLOCKSPRING
(5QUIBjAIR QA$e_MODULE
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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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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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