1997 MITSUBISHI TRITON wiring

SRS ± Troubleshooting52B-14
Code No.43 SRS warning lamp drive circuit system
(Lamp does not switch off.)Probable cause
This diagnosis code is output when a short to earth occurs in the harness between
the lamp and the SDU while SDU is monitoring the SRS warning lamp and the lamp
is ON.
Malfunction of wiring harnesses or connectors

Malfunction of SDU

Malfunction of combination meter
SRS warning lamp inspection

Ignition switch: ON

Does lamp switch off when SDU connector C-27 is
disconnected?NoCheck the following
connectos:
C-06, C-27NG
Repair
Ye s
Replace the SDU.
OK
Check trouble symptoms.
NG
Check the harness wire
between the SDU and
combination meter, and
repair if necessary.
Code No.44 SRS warning lamp drive circuit systemProbable cause
This diagnosis code is output when a short occurs in the lamp drive circuit or a
malfunction of the output transistor inside the SDU is detected while the SDU is
monitoring the SRS warning lamp drive circuit.
Malfunction of wiring harnesses or connectors

Malfunction of SDU
Check the SRS warning lamp drive circuit system.
(Refer to P.52B-13.)OKReplace the SDU.
Code No.45 SDU non-volatile memory (EEPROM) and A/D
converter systemProbable cause
This diagnosis code is output if there is a malfunction in the SDU non-volatile memory
(EEPROM) and A/D converter.
Malfunction of SDU
Replace the SDU.
INSPECTION CHART FOR TROUBLE SYMPTOMS52400340126
Get an understanding of the trouble symptoms and check according to the inspection procedure chart.
Trouble symptomInspection procedure No.Reference page
Communication with
MUT-II is not possible.Communication with all systems is not
possible.152B-15
Communication is not possible with
SRS only.252B-15
When the ignition key is turned to ªONº (engine stopped), the
SRS warning lamp does not illuminate.Refer to diagnosis code No.43.52B-13
After the ignition switch is turned to ON, the SRS warning lamp
is still on after approximately 7 seconds have passed.Refer to diagnosis code No.43.52B-14

SRS ± Post-collision Diagnosis52B-19
POST-COLLISION DIAGNOSIS52400110154
To inspect and service the SRS after a collision (whether
or not the air bag has deployed), perform the following steps.
SRS DIAGNOSIS UNIT MEMORY CHECK
1. Connect the MUT-II to the diagnosis connector (16-pin).
Caution
Turn off the ignition switch before connecting or
disconnecting the MUT-II.
2. Read (and write down) all displayed diagnosis codes.
(Refer to P. 52B-6.)
NOTE
If the battery power supply has been disconnected or
disrupted by the collision, the MUT-II cannot communicate
with the SRS diagnosis unit. Inspect and, if necessary,
repair the body wiring harness before proceeding further.
3. Read the data list (fault duration and how many times
memories are erased) using the MUT-II.
Data list
No.Service Data ItemApplicability
91How long a problem has lastedMaximum time to be stored: 9999 minutes
(approximately 7 days)
92Number indicating houw often the memory is clearedMaximum time to be stored: 250
4. Erase the diagnosis codes and after waiting 5 seconds
or more read (and write down) all displayed diagnosis
codes. (Refer to P.52B-6.)
REPAIR PROCEDURE
WHEN AIR BAG DEPLOYS IN A COLLISION.
1. Replace the following parts with new ones.

SRS diagnosis unit (SDU) (Refer to P. 52B-26.)

Air bag module (Refer to P. 52B-28.)

Front impact sensors (Refer to P. 52B-23.)

11
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
None of the doors can be locked or unlocked using
the transmitter.Probable cause
The cause may be a malfunction of the transmitter or ETACS-
ECU, defective connection between ETACS-ECU and junction
block, defective power supply voltage to ETACS-ECU input
line due to commercial equipment, or the lock and unlock sig-
nals are not being sent to the ETACS-ECU.•
Malfunction of transmitter
•
Malfunction of ETACS-ECU
•
Malfunction of key reminder switch
•
Malfunction of wiring harness or connector
•
Malfunction of door switch
•
Defective connection between ETACS-ECU and
junction block
•
Defective power supply voltage to ETACS-ECU
input line due to commercial equipment
Check the central door lock systemCan the doors be locked and unlocked by the pas-
senger’s-side door key cylinder and lock knob?
YesNo
Has the encrypted code been registered properly? * NG Re-register the encrypted code. (Refer to P.42.6)
OK
Replace the transmitter battery. (Refer to P.42-6)
NG
Is a commercial equipment equipped?
NoYes
Remove that equipment, and then check trouble
symptoms.
NG
Check the connection between ETACS-ECU and
junction block claw.NG
Repair
OK
NG .Check the following connectors:
A-56X, C-81, C-91
OK NG
Measure at the ETACS-ECU connector C-91.
•
Disconnect the connector, and measure at the
harness side.
•
Voltage between 2 and body earth
OK:
System voltageCheck trouble symptomsRepair
OK NG
Check the harness wire, and repair if necessary.
•
Between fusible link No.5 and ETACS-ECU
Door switch continuity check
OK NG
Mut-II Pulse Check
•
Door switch input signal
OK:
MUT-II Buzzer sounds once when opening
and closing each door.NG
Repair
OK
Check the following connectors:
C-110, D-03, D-07, D-14, D-17, D-21
OK NG
Check trouble Symptoms.Repair
NG
To next pageCheck the harness wire, and repair if necessary.
•
Between ETACS-ECU and door switch
NOTE
*: This should be done if a transmitter, receiver or ETACS-ECU has been replaced, and if a secret cod
has not been registered properly
BODY – Keyless Entry System42-3

12From previous page
Key reminder switch continuity check
OK NG
MUT-II Pulse Check
•
Key reminder switch input signal
OK:
MUT-II buzzer sounds once when removing
and inserting ignition key.NG
Repair
OK
Check the following connectors:
C-72, C-79, C-86, C-91
Replace the transmitter.OK NG
OK
Check trouble symptomsRepair
Check the trouble symptoms.NG
OK
Replace the ETACS-ECU.
Check the harness wire, and repair if necessary.
•
Between key reminder switch and ETACS-ECU
•
Between key reminder switch and earth
INSPECTION PROCEDURE 2
All of the doors can be locked and unlocked using th
transmitter, but the room lamp or turn-signal lamp does
not flash or illuminate. (However, the room lamp oper-
ates normally when the doors are opened and closed.)Probable cause
If neither room lamp nor turn-signal lamp flash/illuminate, the
cause may be a malfunction of the ETACS-ECU or driver’s-side
door lock actuator.
If either room lamp or turn-signal lamp does not flash/illuminate,
the cause may be a malfunction of the room lamp circuit or turn-
signal lamp.•
Malfunction of ETACS-ECU
•
Malfunction of driver’s door lock actuator
•
Burnt turn-signal lamp bulb
•
Malfunction of connector or wiring harness
Carry out the troubleshooting for room lamp circuit.Does the room lamp go on/go off simultaneous
with opening/closing door?NO
Yes
Does the turn-signal lamp flash when the turn-
signal lamp switch is operated?NO
Carry out the troubleshooting for turn-signal lamp
circuit.
Yes
NG
Check the driver’s door lock actuator
OK NG
MUT-II Pulse Check
•
Drivers door lock actuator switch input signal
OK:
MUT-II buzzer sounds once when locking
or unlocking driver’s door.Replace
OKCheck the following connectors:
C-38, C-110, E-09 ,
E-20
Replace the ETACS-ECUOK NG
Check trouble symptoms.Repair
NG
Check the harness wire, and repair if necessary.
•
Between ETACS-ECU and driver’s door lock actua-
tor
•
Between driver’s door lock actuator and earth
42-4BODY – Keyless Entry System

13
INSPECTION PROCEDURE 3
Encrypted codes cannot be registered Probable cause
The cause may be a malfunction of the diagnosis con-
nector, ETACS-ECU or diagnosis output circuit.•
Malfunction of MUT-II
•
Malfunction of connector or wiring harness
•
Malfunction of ETACS-ECU
NGCheck the following connectors:
C-35, D-110
OK NG
Check trouble symptomsRepair
NG
Measure at diagnosis connector C-35 and ETACS-
ECU connector D-110.
•
Disconnect the connector, and measure at har
ness side.
•
Continuity between following terminals:
OK:
Continuity
28 - 9 side>Check the harness wire, and repair if necessary.
•
Between the ETACS-ECU and diagnosis connector
OK
Can the MUT-II communicate with other systems?
Yes No
NGCheck the following connectors:
A-56X, C-35, C-79, C-81
OK NG
Check trouble symptoms.Repair
Measure at the diagnosis
connector C-35
•
Voltage between 16
and body earth
OK:
System voltage
NG
OKCheck the harness wire, and repair if necessary.
•
Between fusible link No.5 and diagnosis connector
OK
Replace MUT-II.Measure at the diagnosis
connector C-35.
•
Continuity between 4
and body earth
•
Continuity between 5
and body earth
OK:
System voltage
NG
NG
RepairCheck the following
connectors:
C-35, C-86
OK
Check trouble symptoms.NG
Check the harness wire, and repair if necessary.
•
Between the diagnosis connector and earth
NG
Check the following connectors:
A-56X, C-81, C-82, C-88, C-91
OK NG
Check trouble symptomsRepair
NG
Measure at the ETACS-ECU connector C-91.
•
Disconnect the connector, and measure at the
harness side
•
Voltage between 1 and body earth
•
Voltage between 2 and body earth
•
Voltage between 3 and body earth
OK:
System voltage
OKCheck the harness wire, and repair if necessary.
•
Between dedicated fuse No.6 and ETACS-ECU
•
Between ignition switch (IG1) and ETACS-ECU
Check the following connectors:
C-86, C-91
OK NG
Check trouble symptoms.
Repair
Measure at the ETACS-ECU connectors C-91
•
Disconnect the connector, and measure at the
harness side.
•
Between 10 for connector C-91 and body earth
OK:
System voltage
NG
OK
Replace the ETACS-ECU.Check the harness wire, and repair if necessary.
•
Between the ETACS-ECU and earth
BODY – Keyless Entry System42-5

10
TROUBLESHOOTING
INSPECTION CHART FOR DIAGNOSIS CODES
Inspect according to the inspection chart that is appropriate for the malfunction code.
Code No. Diagnosis item Reference page
14 Analog G-sensor system in the SRS-ECU -
15, 16 Safing G-sensor system in the SRS-ECU -
21, 22, 61, 62 Driver’s side air bag module (squib) system 52B-5
24, 25, 64, 65 Front passenger’s side air bag module (squib) system 52B-6
31, 32 SRS-ECU capacitor system -
34* Connector lock system -
35 SRS-ECU capacitor system -
41* IG1 (A) power circuit system 52B-7
42* IG1 (B) power circuit system 52B-7
43 SRS warning lamp drive circuit system Lamp does not illuminate. * 52B-7
Lamp does not switch off. -
44 SRS warning lamp drive circuit system -
45 SRS-ECU non volatile memory (EEPROM) and A/D converter system -
51, 52 Driver’s side air bag module (squib ignition drive circuit) system -
54, 55 Front passenger’s side sir bag module (squib ignition drive circuit) system -
NOTE
(1) *: if the vehicle condition return to normal, the diagnosis code will be automatically erased, and the SRS warning
lamp will return to normal.
(2) If the vehicle has a discharged battery it will store the fault codes 41 or 42. When these diagnosis codes are
displayed, check the battery.
INSPECTION PROCEDURE CLASSIFIED BY DIAGNOSIS CODE
Code No. 21,22, 61 or 62 Driver’s side air bag module
(squib) systemProbable cause
These diagnosis codes are output if there is abnormal resistance between the
input terminals of the driver’s side air bag module (squib).
The trouble causes for each diagnosis code No. are as follows.·
Malfunction of clock spring
·
Open-circuit in clock spring due to inappropriate neutral
position.
·
Malfunction of wiring harnesses or connectors
·
Malfunction of driver’s side air bag module (squib)
·
Malfunction of SRS-ECU
Code No. Trouble symptoms
21
·
Short in driver’s side air bag module (squib) or harness short
·
Short in clock spring
22
·
Open circuit in driver’s side air bag module (squib) or open harness
·
Open circuit in clock spring
·
Disconnected connector in the driver’s side air bag module (squib).
·
Open circuit in clock spring due to inappropriate neutral position.
·
Malfunction of connector contact
61
·
Short in driver’s side air bag module (squib) harness leading to the power supply
62
·
Short in driver’s side air bag module (squib) harness leading to the earth
52B-5SRS - Troubleshooting