Mitsubishi Outlander (2013+). Manual - part 609

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-87

STEP 6. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code No. B1603 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.B1604 Seat belt pre-tensioner (driver’s side) (squib) system (open circuit of squib circuit)

CAUTION

If the diagnosis code B1604 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 
and safing G-sensor in SRS-ECU, the electric cur-
rent is supplied from SRS-ECU to the seat belt 
pre-tensioner (squib).

TROUBLE JUDGEMENT

The code is set when the open circuit occurs to the 
SRS-ECU seat belt pre-tensioner (driver’s side) 
(squib) circuit.

PROBABLE CAUSES

• Open circuit to seat belt pre-tensioner (driver’s 

side) (squib) circuit

• Damaged wiring harness and 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. B1604 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.

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 
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 the 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 

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-88

the diagnosis code again.

(7) Disconnect the negative battery terminal.

Q: Is the diagnosis code No. B1604 set?

YES : 

Go to Step 4.

NO : 

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

P.52B-147

).

STEP 4. Resistance measurement at the 
SRS-ECU connector and the seat belt 
pre-tensioner (driver's side) 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 the short spring, and release the short spring.

AC201287 GJ

MB991884 

(Resistor harness)

Harness side 
connector

(5) Connect special tool resistor harness 

(MB991884) to the removed seat belt 
pre-tensioner (driver's side) harness side 
connector.

AC506985FH

2

1

SRS-ECU 
harness side 
connector (front view)

Resistor harness side 

connector (front view)

(6) Take the measurements below at the resistor 

harness and SRS-ECU harness side connector. 

• Continuity PTD- line between SRS-ECU con-

nector and resistor harness connector

• Continuity PTD+ line between SRS-ECU con-

nector and resistor harness connector

OK: Continuity (less than 2 

Ω)

Q: Is the check result normal?

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-89

YES : 

Go to Step 5.

NO : 

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

STEP 5. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code No. B1604 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.B1605 Seat belt pre-tensioner (driver’s side) (squib) system (shorted to squib circuit earth)

CAUTION

If the diagnosis code B1605 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 input terminal of SRS-ECU 
seat belt pre-tensioner (driver’s side) (squib) is 
shorted to earth

PROBABLE CAUSES

• Damaged wiring harness and connector

• Seat belt pre-tensioner (driver’s side) (squib) har-

ness 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. B1605 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.

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 
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 

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-90

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. B1605 set?

YES : 

Go to Step 4.

NO : 

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

P.52B-147

).

STEP 4. 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.

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 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 and 

body earth

OK: No continuity

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

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

STEP 5. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code No. B1605 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 ).