Mitsubishi Outlander (2013+). Manual - part 598

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-43

STEP 6. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code No. B1420 set?

YES : 

Replace SRS-ECU (Refer to 

P.52B-129

).

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

Code No.B1421 Right side-airbag module (squib) system (open circuit of squib circuit)

CAUTION

If the diagnosis code B1421 is set to SRS-ECU, 
be sure to diagnose the CAN bus line.

OPERATION

In case of side collision, when the impact exceeding 
the threshold is applied to the vehicle, and when the 
impact is simultaneously detected (turned ON) by the 
side impact sensor as well as by the analogue 
G-sensor in SRS-ECU, the electric current is sup-
plied from SRS-ECU to the side-airbag module 
(squib) of impacted side.

TROUBLE JUDGEMENT

The code is set when the open circuit occurs to the 
SRS-ECU side-airbag module (squib) circuit.

PROBABLE CAUSES

• Open circuit to side-airbag module (squib) circuit

• Poor contact of connector

• Malfunction of SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-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 
54C 

− Troubleshooting ).

STEP 2. Check whether the diagnosis code is 
reset.
(1) Connect the negative battery terminal.
(2) After erasing the diagnosis code memory, check 

the diagnosis code again.

(3) Disconnect the negative battery terminal.

Q: Is the diagnosis code No. B1421 set?

YES : 

Go to Step 3.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

STEP 3. Diagnosis check by dummy resistor 
connection.
(1) Check that the negative battery terminal is 

disconnected. If the negative battery terminal is 
connected, disconnect it.

AC706606

AC

Locking button

Side-airbag module
connector

(2) Disconnect the right side-airbag module 

connector, unlock the connector by sliding the 
locking button to the direction of the arrow as 
shown in the figure, and then disconnect the 
connector.

AC507310BS

Side-airbag 
module (RH) connector

Harness 
side connector

MB991865
(Dummy resistor: 3    )

MB991866 

(Resistor harness)

(3) Connect special tool dummy resistor (MB991865) 

to special tool resistor harness (MB991866).

CAUTION

Do not insert a probe directly into the terminal 
from the connector front side as the connector 
contact pressure may be weakened.
(4) Insert the resistor harness probe from the back of  

right side-airbag module harness side connector.

(5) Connect the negative battery terminal.
(6) After erasing the diagnosis code memory, check 

the diagnosis code again.

(7) Disconnect the negative battery terminal.

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-44

Q: Is the diagnosis code No. B1421 set?

YES : 

Go to Step 4.

NO : 

Replace the front seatback pad and frame 
assembly (Refer to 

P.52B-142

).

STEP 4. Resistance measurement at the 
SRS-ECU connector and the right side-airbag 
module connector.
(1) Check that the negative battery terminal is 

disconnected. If the negative battery terminal is 
connected, disconnect it.

AC905015

A

AC

Lock lever

(2) While pushing the part "A" indicated in the figure 

of the harness side connector, turn the lock lever 
to the direction of the arrow to release the lock 
lever, and disconnect the SRS-ECU connector.

DANGER

To release the connector short spring in the 
following operations, disconnect this 
side-airbag module connector, and keep the 
squib circuit shorted.

AC706606

AC

Locking button

Side-airbag module
connector

(3) Disconnect the right side-airbag module 

connector, unlock the connector by sliding the 
locking button to the direction of the arrow as 
shown in the figure, and then disconnect the 

connector.

AC905468AR

A

A

Harness side
connector (front view)

Section
A - A

Cable tie

Short spring

4 mm or more

Terminal

CAUTION

The short spring may not be released due to the 
insufficient insertion, thus insert for 4 mm or 
more.
(4) Insert a cable tie (width: 3 mm, thickness: 0.5 

mm) between the SRS+, SRS- line and the short 
spring, and then release the short spring.

CAUTION

Do not insert a test probe directly into the termi-
nal of  right side-airbag module harness side 
connector from the connector front side as the 
connector contact pressure may be weakened.
(5) Take the measurements below at the SRS-ECU 

and right side-airbag module harness side 
connectors. 

• Continuity SRS+ line between SRS-ECU con-

nector and right side-airbag module connec-
tor

• Continuity SRS- line between SRS-ECU con-

nector and right side-airbag module connec-
tor

OK: Continuity (less than 2 

Ω)

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the wiring harness SRS+, SRS- line 
between the right side-airbag module 
connector and the SRS-ECU connector.

STEP 5. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code No. B1421 set?

YES : 

Replace SRS-ECU (Refer to 

P.52B-129

).

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-45

Code No.B1422 Right side-airbag module (squib) system (shorted to squib circuit earth)

CAUTION

If the diagnosis code B1422 is set to SRS-ECU, 
be sure to diagnose the CAN bus line.

OPERATION

In case of side collision, when the impact exceeding 
the threshold is applied to the vehicle, and when the 
impact is simultaneously detected (turned ON) by the 
side impact sensor as well as by the analogue 
G-sensor in SRS-ECU, the electric current is sup-
plied from SRS-ECU to the side-airbag module 
(squib) of impacted side.

TROUBLE JUDGEMENT

The code is set when the input terminal of SRS-ECU 
side-airbag module (squib) is shorted to earth.

PROBABLE CAUSES

• Damaged wiring harness and connectors

• side-airbag module (squib) harness shorted to 

earth

• Malfunction of SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-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 
54C 

− Troubleshooting ).

STEP 2. Check whether the diagnosis code is 
reset.
(1) Connect the negative battery terminal.
(2) After erasing the diagnosis code memory, check 

the diagnosis code again.

(3) Disconnect the negative battery terminal.

Q: Is the diagnosis code No. B1422 set?

YES : 

Go to Step 3.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

STEP 3. Diagnosis check by dummy resistor 
connection.
(1) Check that the negative battery terminal is 

disconnected. If the negative battery terminal is 

connected, disconnect it.

AC706606

AC

Locking button

Side-airbag module
connector

(2) Disconnect the right side-airbag module 

connector, unlock the connector by sliding the 
locking button to the direction of the arrow as 
shown in the figure, and then disconnect the 
connector.

AC507310BS

Side-airbag 
module (RH) connector

Harness 
side connector

MB991865
(Dummy resistor: 3    )

MB991866 

(Resistor harness)

(3) Connect special tool dummy resistor (MB991865) 

to special tool resistor harness (MB991866).

CAUTION

Do not insert a probe directly into the terminal 
from the connector front side as the connector 
contact pressure may be weakened.
(4) Insert the resistor harness probe from the back of 

right harness side connector.

(5) Connect the negative battery terminal.
(6) After erasing the diagnosis code memory, check 

the diagnosis code again.

(7) Disconnect the negative battery terminal.

Q: Is the diagnosis code No. B1422 set?

YES : 

Go to Step 4.

NO : 

Replace the front seatback pad and frame 
assembly (Refer to 

P.52B-142

).

STEP 4. Resistance measurement at the 
SRS-ECU connector.
(1) Check that the negative battery terminal is 

disconnected. If the negative battery terminal is 

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-46

connected, disconnect it.

AC905015

A

AC

Lock lever

(2) While pushing the part "A" indicated in the figure 

of the harness side connector, turn the lock lever 
to the direction of the arrow to release the lock 
lever, and disconnect the SRS-ECU connector.

DANGER

To release the connector short spring in the 
following operations, disconnect this 
side-airbag module connector, and keep the 
squib circuit shorted.

AC706606

AC

Locking button

Side-airbag module
connector

(3) Disconnect the right side-airbag module 

connector, unlock the connector by sliding the 
locking button to the direction of the arrow as 
shown in the figure, and then disconnect the 

connector.

AC905468AR

A

A

Harness side
connector (front view)

Section
A - A

Cable tie

Short spring

4 mm or more

Terminal

CAUTION

The short spring may not be released due to the 
insufficient insertion, thus insert for 4 mm or 
more.
(4) Insert a cable tie (width: 3 mm, thickness: 0.5 

mm) between the SRS+, SRS- line and the short 
spring, and then release the short spring.

(5) Take the measurements below at the SRS-ECU 

harness side connector.

• Continuity between SRS+, SRS- line and 

body earth

OK: No continuity

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the wiring harness SRS+, SRS- line 
between the SRS-ECU connector and the 
right side-airboat module connector.

STEP 5. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code No. B1422 set?

YES : 

Replace SRS-ECU (Refer to 

P.52B-129

).

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

Code No.B1423 Right side-airbag module (squib) system (shorted to squib circuit power supply)

CAUTION

If the diagnosis code B1423 is set to SRS-ECU, 
be sure to diagnose the CAN bus line.

OPERATION

In case of side collision, when the impact exceeding 
the threshold is applied to the vehicle, and when the 
impact is simultaneously detected (turned ON) by the 
side impact sensor as well as by the analogue 
G-sensor in SRS-ECU, the electric current is sup-

plied from SRS-ECU to the side-airbag module 
(squib) of impacted side.

TROUBLE JUDGEMENT

The code is set when the input terminal of SRS-ECU 
side-airbag module (squib) is shorted to power sup-
ply.

PROBABLE CAUSES

• Damaged wiring harness and connectors