Mitsubishi Grandis. Manual — part 1032

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-180

• 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 an open circuit has
occurred in the wiring harness between the
passenger’s air bag off indicator lamp and the
SRS-ECU. If the vehicle condition returns to normal,
diagnosis code B1489 will be automatically erased,
and the passenger’s air bag off indicator 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 light

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, always turn the
ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting MUT-III.
(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 MUT-III actuator test.

• Item No.03: Passenger’s air bag off indicator

lamp illumination

Q: Does the passenger’s air bag off indicator lamp

illuminate or go out normally?
YES :

Go to Step 5 .

NO :

Replace the passenger’s air bag off
indicator lamp (Refer to GROUP 52A,
Instrument Panel Assembly

P.52A-2

). Then

go to Step 6 .

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-181

STEP 5. Check the harness between SRS-ECU
connector C-119 (terminal No.21) and
passenger’s air bag off indicator lamp C-25
(terminal No.3).

• Check the passenger’s air bag off indicator lamp

output lines for open circuit.

Q: Is the check result satisfactory?

YES :

Erase the diagnosis code memory, and

check the diagnosis code. If diagnosis
B1489 sets, replace the SRS-ECU. (Refer
to

P.52B-223

.) Then go to Step 6 .

NO :

Repair the harness wires. Then go to Step 6
.

STEP 6. Check whether the diagnosis code is
reset.

Q: Is diagnosis code B1489 set?

YES :

Return to Step 1 .

NO :

The procedure is complete.

Code No. B1499: SRS-ECU Air Bag Condition Monitor Detects Deployed Air Bag

CAUTION

If diagnosis code B1499 is set in the SRS-ECU,
always diagnose the CAN main bus line.

TROUBLE JUDGMENT

This diagnosis code is set after the air bag has
deployed. If this diagnosis code is set before the air
bag has deployed, the cause is probably a
malfunction inside the SRS-ECU.

PROBABLE CAUSES

Malfunction of the SRS-ECU

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?

AC310613

BI

Connector: C-25 <LHD>

Harness side

AC310631BE

Connector: C-25 <RHD>

Harness side

AC311438 AD

C-119 (Y)

Connector: C-119

Harness side
(front view)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-182

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 B1499 set?

YES :

Replace the SRS-ECU (Refer to

P.52B-223

).

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

).

Code No.B1506: Seat Slide Sensor System Fault 1 (Open in the Seat Slide Sensor Circuit)

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

SRS-ECU

SEAT SLIDE
SENSOR

Seat Slide Sensor Circuit <LH drive vehicles>

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-183

CAUTION

If diagnosis code B1506 is set in the SRS-ECU,
always diagnose the CAN main bus line.

OPERATION

• The seat slide sensor sets the current value Hi or

Low determined by the seat position.

• The SRS-ECU determines the seat position

according to the current value from the seat slide
sensor.

DIAGNOSIS CODE SET CONDITIONS

• This diagnosis code is set if there is abnormal

resistance between the input terminals of the
seat slide sensor. The most likely causes for this
code to be set are the followings:

• Open circuit in the seat slide sensor or

harness

• Malfunction of connector contact

However, if no diagnosis code reset, the SRS
warning lamp will be switched off (diagnosis code will
be retained).

PROBABLE CAUSES

• Open circuit in the seat slide sensor circuit

• Disengaged seat slide sensor connector

• Improper connector contact

• Malfunction of the SRS-ECU

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

).

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

SRS-ECU

SEAT SLIDE
SENSOR

Seat Slide Sensor Circuit <RH drive vehicles>