Mitsubishi Outlander (2013+). Manual - part 608

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-83

PROBABLE CAUSES

• Malfunction of the passenger’s air bag cut off 

switch

• Damaged wiring harnesses or connectors 

• Malfunction of the SRS-ECU 

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the 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 lines (Refer to GROUP 
54C, Diagnosis-Can Bus Diagnostic Chart ).

STEP 2. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set.
(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.B1570, B1573, B1574 or 

B1575 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. Check the passenger’s air bag cut off 
switch.
Check of a passenger’s air bag cut off switch (Refer 
to 

P.52B-152

).

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Replace passenger’s air bag cut off switch 
(Refer to 

P.52B-150

.)

STEP 4. Check the passenger’s air bag cut off 
switch circuit. Resistance measurement at 
SRS-ECU 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.

(3) Switch the passenger’s air bag cut off switch to 

air bag ON side.

(4) Measure the resistance between POF-, POFO 

line.

OK: 820 

± 20 Ω

(5) Switch the passenger’s air bag cut off switch to 

air bag OFF side.

(6) Measure the resistance between POF-, POFO 

line.

OK: Continuity (less than 2 

Ω)

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the harness wires POF-, POFO line 
between SRS-ECU connector and 
passenger’s air bag cut off switch 
connector.

STEP 5. Resistance measurement at the 
SRS-ECU 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.

B1574

Malfunction of the common terminal 
or open circuit in its harness

B1575

Short to body earth in the common 
terminal harness

Code No.

Symptom

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-84

(3) Disconnect the passenger’s air bag cut off switch 

connector. 

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

harness side connector.

• Continuity between POF-, POFO line and 

body earth

OK: No continuity

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the harness wires POF-, POFO line 
between SRS-ECU connector and 
passenger’s air bag cut off switch 
connector.

STEP 6. Voltage measurement at the SRS-ECU 
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.

(3) Disconnect the passenger’s air bag cut off switch 

connector. 

(4) Connect the negative battery terminal.
(5) Ignition switch: ON
(6) Take the measurements below at the SRS-ECU 

harness side connector.

• Voltage between POF-, POFO line and body 

earth

OK: 1 V or less

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Repair the harness wires POF-, POFO line 
between SRS-ECU connector and 
passenger’s air bag cut off switch 
connector.

STEP 7. Check whether the diagnosis code is 
reset.

Q: Is diagnosis code No.B1570, B1573, B1574 or 

B1575 set?
YES : 

Replace the SRS-ECU (Refer to 

P.52B-129

). 

NO : 

An intermittent malfunction is suspected 
(Refer to GROUP 00 

− How to Cope with 

Intermittent Malfunction ). 

Code No.B1603 Seat belt pre-tensioner (driver’s side) (squib) system (short circuit between squib 
circuit terminals)

CAUTION

If the diagnosis code B1603 is set to SRS-ECU, 
be sure to diagnose the CAN bus line.

OPERATION

Only when the frontal impact exceeding the threshold 
is simultaneously detected (turned ON) by the front 
impact sensor as well as by the analogue G-sensor 
in SRS-ECU, the electric current is supplied from 
SRS-ECU to the seat belt pre-tensioner (squib).

TROUBLE JUDGEMENT

The code is set when the short circuit occurs 
between the terminals of SRS-ECU seat belt pre-ten-
sioner (driver’s side) (squib) circuit.

PROBABLE CAUSES

• Damaged short spring 

*

• Short circuit between terminals of seat belt 

pre-tensioner (driver’s side) (squib) circuit

• Damaged connector(s)

• Malfunction of SRS-ECU

• Insufficient press of locking button or locking but-

ton not pressed

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-85

NOTE: *: The squib circuit connectors integrate a 
short spring (which prevents the seat belt pre-ten-
sioner from being unintentionally deployed because 
of static electricity by shorting the positive wire to the 
earth wire in the squib circuit when the connectors 
are disconnected). Therefore, when the above codes 
are set, the short spring may not be released due to 
the damaged connector even when the connectors 
are connected.

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. B1603 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. Connector check: SRS-ECU, seat belt 
pre-tensioner (driver’s side).
(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. After disconnecting the SRS-ECU 
connector, connect it again.

ACC00046AB

Locking button

Flat-tipped
screwdriver

Seat belt pre-tensioner 
harness side connector

(3)  After disconnecting the seat belt pre-tensioner 

(driver's side) harness side connector, connect 
the connector again. For the seat belt 
pre-tensioner (driver's side) harness side 
connector disconnection, use the flat-tipped 
screwdriver to pull out the harness side 
connector locking button. After releasing the lock, 
disconnect the harness side connector.

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

the diagnosis code again.

(6) Disconnect the negative battery terminal.

Q: Is the diagnosis code No. B1603 set?

YES : 

Go to Step 4.

NO : 

Replace the connector concerned.

STEP 4. Diagnosis check by dummy resistor 
connection.
(1) Check that the negative battery terminal is 

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

ACC00046AB

Locking button

Flat-tipped
screwdriver

Seat belt pre-tensioner 
harness side connector

(2) Use the flat-tipped screwdriver to pull out the 

locking button of harness side connector. After 
releasing the lock, disconnect the seat belt 
pre-tensioner (driver's side) harness side 

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-86

connector. 

AC301553DR

Harness side 
connector

MB991865

(Dummy resistor: 3    )

MB991884 

(Resistor harness)

(3) Connect special tool dummy resistor (MB991865) 

to special tool resistor harness (MB991884).

(4) Connect special tool resistor harness to the seat 

belt pre-tensioner (driver's side) 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. B1603 set?

YES : 

Go to Step 5.

NO : 

Replace the seat belt with pre-tensioner 
(driver’s side) (Refer to 

P.52B-147

).

STEP 5. Resistance check at the SRS-ECU 
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 SRS-ECU connector short 
spring in the following operations, discon-
nect this seat belt pre-tensioner connector, 
and keep the squib circuit shorted.

ACC00046AB

Locking button

Flat-tipped
screwdriver

Seat belt pre-tensioner 
harness side connector

(3) Use the flat-tipped screwdriver to pull out the 

locking button of harness side connector. After 
releasing the lock, disconnect the seat belt 
pre-tensioner (driver's side) harness side 
connector.

AC905468AU

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. Therefore, insert the insu-
lator for 4 mm or more.
(4) Insert an insulator (width: 3 mm, thickness: 0.5 

mm) such as cable tie between the PTD-, PTD+ 
line and the short spring, and release the short 
spring.

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

harness side connector. 

• Continuity between PTD-, PTD+ line

OK: No continuity

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness PTD-, PTD+ line 
between the SRS-ECU connector and the 
seat belt pre-tensioner (driver's side) 
connector.