Mitsubishi Montero Sport (2004+). Manual — part 748

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-61

DTC 46 Improper installation of SRS-ECU

.

DTC SET CONDITIONS
This DTC is set when an SRS-ECU, designed only
for the driver's air bag, is installed on the vehicle,
which has both driver's and passenger's air bags.

.

TROUBLESHOOTING HINTS

• Malfunction of the SRS-ECU

.

DIAGNOSIS
Replace the SRS-ECU (Refer to

P.52B-82

).

SRS WARNING LIGHT CHECK

M1524004300402

1. Check that the SRS warning light illuminates when the

ignition switch is in the "ON" position.

2. Check that it illuminates for approximately 7 seconds and

then goes out.

3. If not, check for DTC.

SYMPTOM CHART

M1524003400558

AC003277AC

SRS WARNING LIGHT

SYMPTOM

INSPECTION
PROCEDURE NO.

REFERENCE PAGE

Communication with scan tool MB991958 is not
possible is not possible with all system.

1

P.52B-62

Communication with scan tool MB991958 is not
possible with SRS system only.

2

P.52B-63

When the ignition key is turned to "ON" (engine
stopped), the SRS warning light does not illuminate.

Refer to DTC No.43.

P.52B-54

After the ignition switch is turned to "ON," the SRS
warning light does not go off within approximately 7
seconds.

Refer to DTC No.43.

P.52B-54

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-62

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: Communication with Scan Tool MB991502 is not Possible with all
System.

.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably a power supply system
(including ground circuit) of the diagnostic line.

.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors.

DIAGNOSIS

Refer to GROUP 13A, Symptom procedure

P.13A-716

.

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-63

INSPECTION PROCEDURE 2: Communication with Scan Tool MB991958 is not Possible with the SRS
System Only.

Scan tool Communication Circuit

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-64

.

CIRCUIT OPERATION

• The SRS-ECU is powered from the ignition

switch (IG

1

).

• The SRS-ECU power is supplied from two cir-

cuits. Even if one circuit is shut off, the air bag
can inflate.

• The SRS system diagnosis can be done by con-

necting scan tool MB991502 to the data link con-
nector.

• The SRS-ECU judges how severe a collision is

by detecting signals from the left and right front
impact sensors and the analog G-sensor. If the
impact is over a predetermined level, the
SRS-ECU outputs an ignition signal. At this time,
if the safing G-sensor is on, the SRS air bag will
inflate.

.

TECHNICAL DESCRIPTION (COMMENT)
If communication is not possible with the SRS only,
the cause is probably an open circuit in the on-board
diagnostic output circuit of the SRS or in the power
circuit (including ground circuit).

.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors

• Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tool:
MB991222: Probe

AC003303 AC

CONNECTOR: C-10

C-10

AC003288

CONNECTOR: C-24

AE

SRS-ECU

C-24 (Y)

AC003304

CONNECTOR: C-69

AC

C-69 (B)

AC003305AC

CONNECTORS: D-08, D-13, D-14

D-13

D-14 (B)

D-08

JUNCTION BLOCK
(REAR)