Mitsubishi Grandis. Manual — part 1030

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-172

• The SRS warning lamp "OFF" signal is not sent

to the combination meter in the cases below,
either. Therefore, the combination meter will
illuminate the SRS warning lamp.

• The SRS-ECU connector is disconnected.

• The SRS-ECU is not working normally due to

a failure in its power supply lines.

• The wiring harness between the passenger’s

air bag off indicator lamp and the SRS-ECU is
broken.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code will be set if the passenger’s air
bag off indicator lamp driving circuit is short to earth.
If the vehicle condition returns to normal, diagnosis
code B1489 will be automatically erased, and the
warning lamp will go out.

PROBABLE CAUSES

• Damaged wiring harnesses or connectors

• Malfunction of the SRS-ECU

• Malfunction of the passenger’s air bag off

indicator lamp

DIAGNOSIS PROCEDURE

STEP 1. MUT-III CAN bus diagnostics

Use the MUT-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair the CAN bus line (Refer to GROUP
54D, Diagnosis

P.54D-16

).

STEP 2. Check whether the diagnosis code is
reset.

Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is

not reset.

Q: Is the diagnosis code set?

YES :

Go to Step 3 .

NO :

There is an intermittent malfunction such as
poor engaged connector(s) or open circuit
(Refer to GROUP 00, How to Cope with
Intermittent Malfunction

P.00-5

).

STEP 3. MUT-III diagnosis code

CAUTION

To prevent damage to MUT-III MB991958, always
turn the ignition switch to the "LOCK" (OFF)
position before connecting or disconnecting
MUT-III MB991958.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the diagnosis code is set.
(3) Turn the ignition switch to the "LOOK (OFF)"

position.

Q: Is diagnosis code B1570, B1571, B1572, B1573,

B1574, B1575, B1576, B1577, B1578, B1579 or
B1581 set?

YES :

Carry out the troubleshooting of the

passenger’s air bag cut off switch system.
(Refer to

P.52B-195

).

NO :

Go to Step 4 .

STEP 4. Check the passenger’s air bag off
indicator lamp connector C-25.

Q: Is the connector correctly engaged?

YES :

Go to Step 5 .

NO :

Engage the connector correctly. Then go to
Step 10 .

AC310613

BI

Connector: C-25 <LHD>

Harness side

AC310631BE

Connector: C-25 <RHD>

Harness side

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-173

STEP 5. Voltage measurement at passenger’s air
bag off indicator lamp connector C-25.

(1) Disconnect passenger’s air bag off indicator lamp

connector C-25.

(2) Measure the voltage between C-25 harness side

connector terminal 1 and body earth.

OK: Approximately 12 volt

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Go to Step 6 .

AC310613

BI

Connector: C-25 <LHD>

Harness side

AC310631BE

Connector: C-25 <RHD>

Harness side

AC308205

C-25 Harness side
connector

AD

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-174

STEP 6. Check the harness for short circuit
between ignition switch connector C-307
(terminal No.2) and passenger’s air bag off
indicator lamp C-25 (terminal No.1).

NOTE:

AC313147AB

Connector: C-307
<L.H.drive vehicles>

C-307

2
5

4

1

6

3

AC313148

AB

Connector: C-307
<R.H.drive vehicles>

C-307

2
5

4

1

6

3

AC310613

BI

Connector: C-25 <LHD>

Harness side

AC310631BE

Connector: C-25 <RHD>

Harness side

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-175

After inspecting intermediate connectors C-202,
C-01 <LHD>, C-33 <RHD> and C-205 inspect the
wiring harness. If intermediate connectors C-202,
C-01 <LHD>, C-33 <RHD> and C-205 are damaged,
repair or replace them. Then go to Step 10 .

Q: Are the harness wires between passenger’s air bag

off indicator lamp connector C-25 (terminal No.1)
and the ignition switch connector C-307 (terminal
No.2) in good condition?

YES :

Go to Step 7 .

NO :

Repair the harness wires. Then go to Step
10 .

STEP 7. Connector check SRS-ECU connector
C-119.

Q: Is SRS-ECU connector C-119 good condition?

YES :

Go to Step 8 .

NO :

Engage the connector correctly. Then go to
Step 10 .

AC310631BD

Connector: C-33 <RHD>

AC310613

AE

Connector: C-01 <LHD>

AC310624

Connectors: C-202, C-205 <LHD>

AF

Junction block (Front view)

C-205

C-202

C-205

Harness side

C-202

Harness side

AC310619

Connectors: C-202, C-205 <RHD>

AF

Junction block (Front view)

C-205

C-202

C-205

Harness side

C-202

Harness side

AC311438 AD

C-119 (Y)

Connector: C-119

Harness side
(front view)