Mitsubishi L200. Manual - part 625

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-171

Code No.B1437: Side impact sensor (LH) voltage error

AC801033

SIDE IMPACT
SENSOR (LH)

SRS-ECU

Side Impact Sensor (LH) 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 : Grey    R : Red     P : Pink     V : Violet     PU : Purple     SI : Silver

AC

SIDE IMPACT SENSOR INTERFACE

OPERATION
The side impact sensor transmits acceleration data 
to the SRS-ECU. The SRS-ECU then determines. if 
the side and/or curtain air bags should be inflated, 
and then sends an ignition signal. The side impact 
sensor also diagnoses itself, and sends a diagnosis 
code to the SRS-ECU if a problem occurs.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code will set when the power supply 
voltage to the side impact sensor (LH) remains less 
than a predetermined value for one second.

PROBABLE CAUSES

• Damaged wiring harness or connectors

• Malfunction of the side impact sensor (LH)

• Malfunction of the SRS-ECU

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-172

DIAGNOSIS PROCEDURE

STEP 1. Check the harness wires for open circuit 
and short circuit between SRS-ECU connector C-
153 (terminal No.15 and 16) and side impact 
sensor (LH) connector D-34 (terminal No.2 and 
1).

AC801404

AL

Connector: C-153

C-153 (Y)

Harness side 
connector 
(rear view)

AC903877

Connector: D-34 <LHD>

<CLUB CAB>

AI

D-34 (Y)

Harness side 
connector 
(rear view)

AC903879AG

Connector: D-34 <RHD>

<CLUB CAB>

D-34 (Y)

Harness side 
connector 
(rear view)

AC903885AP

Connector: D-34 <LHD>

<DOUBLE CAB>

D-34 (Y)

Harness side 
connector 
(rear view)

AC903886 AK

Connector: D-34 <RHD>

<DOUBLE CAB>

D-34 (Y)

Harness side 
connector 
(rear view)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-173

Q: Is the check result normal

YES : 

Go to Step 2.

NO : 

Repair the harness wires between SRS-
ECU connector C-153 (terminal No.15 and 
16) and side impact sensor (LH) connector 
D-34 (terminal No.2 and 1).

STEP 2. Check the side impact sensor (LH).
(1) Disconnect the negative battery terminal.
(2) Alternate the side impact sensor (LH) and the 

side impact sensor (RH), and then install the 
alternated sensor.

(3) Connect the negative battery terminal.
(4) Erase the diagnosis code from memory, and 

check the diagnosis code.

Q: Is diagnosis code B1427 set?

YES : 

Replace the side impact sensor (LH) with a 

new one (Refer to 

P.52B-282

).

NO : 

Go to Step 3.

STEP 3. Check whether the diagnosis code is 
reset.

Q: Is diagnosis code B1437 set?

YES : 

Replace the SRS-ECU (Refer to 

P.52B-

266

).

NO : 

An intermittent malfunction is suspected 
(Refer to GROUP 00, How to Cope with 
Intermittent Malfunction ).

Code No.B1438: Side impact sensor (LH) communication error

 

Code No.B1439: Side impact sensor (LH) communication impossible

AC801033

SIDE IMPACT
SENSOR (LH)

SRS-ECU

Side Impact Sensor (LH) 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 : Grey    R : Red     P : Pink     V : Violet     PU : Purple     SI : Silver

AC

SIDE IMPACT SENSOR INTERFACE

OPERATION
The side impact sensor transmits acceleration data 
to the SRS-ECU. The SRS-ECU then determines. if 
the side and/or curtain air bags should be inflated, 
and then sends an ignition signal. The side impact 
sensor also diagnoses itself, and sends a diagnosis 
code to the SRS-ECU if a problem occurs.

DIAGNOSIS CODE SET CONDITIONS
These diagnosis codes are set if communication 
between the side impact sensor (LH) and the SRS-
ECU is not possible or faulty.

PROBABLE CAUSES

• Damaged wiring harnesses or connectors

• Malfunction of the side impact sensor (LH)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-174

• Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the side impact sensor (LH).
(1) Disconnect the negative battery terminal.
(2) Alternate the side impact sensor (LH) and the 

side impact sensor (RH), and then install the 
alternated sensor.

(3) Connect the negative battery terminal.
(4) Erase diagnosis code from memory, and check 

the diagnosis code.

Q: Is diagnosis code B1428 or B1429 set?

YES : 

Replace the side impact sensor (LH) with a 

new one. (Refer to 

P.52B-282

). Go to Step 

3.

NO : 

Go to Step 2.