Mitsubishi L200. Manual - part 638

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-223

Code No.B1595: Front impact sensor RH system (short circuit in the sensor)

 

Code No.B1596: Front impact sensor RH system (open circuit in the sensor)

 

Code No.B1597: Front impact sensor RH (short circuited in the earth)

 

Code No.B1598: Front impact sensor RH (short circuited in the power supply)

 

Code No.B1599: Front impact sensor LH system (short circuit in the sensor)

 

Code No.B1600: Front impact sensor LH  (open circuit in the sensor)

 

Code No.B1601: Front impact sensor LH (short circuited in the earth)

 

Code No.B1602: Front impact sensor LH (short circuited in the power supply)

AC903656

Front Impact Sensor Circuit

SRS-ECU

FRONT IMPACT
SENSOR (RH)

FRONT IMPACT
SENSOR (LH)

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

AB

NOTE

: RHD

: LHD

OPERATION

• When the left and right front impact sensors 

detect a collision, the switches inside the sensors 
turn ON. 

• SRS-ECU judges how severe a collision is by 

detecting signals from the front impact sensors 
and the front air bag analogue G-sensor. If the 
impact is over a predetermined level, the SRS-
ECU sends an ignition signal. At this time, if the 
front air bag safing G-sensor is on, the SRS air 
bag will inflate. 

DIAGNOSIS CODE SET CONDITIONS
These diagnosis codes are set if these are abnormal 
resistance between the input terminals of the front 
impact sensors.
The most likely causes for these codes to be set are 
shown in the table below:

Code No.

Trouble causes

B1595

Right front impact sensor or its wiring shorted

B1596

Right front impact sensor or wiring open circuit

B1597

Short to body earth in the right front impact sensor harness

B1598

Short to the power supply in the right front impact sensor harness

B1599

Left front impact sensor or its wiring shorted

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-224

PROBABLE CAUSES

• Damaged harness wires and connectors

• Front impact sensor failed

• Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the front impact sensor.
 Refer to 

P.52B-264

.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Check the harness wires for open or short 
circuit between intermediate connector and 
front impact sensor, and repair if necessary. 
Then replace the front impact sensor (Refer 
to 

P.52B-263

).

STEP 2. Resistance measurement at the SRS-
ECU connector C-154.
(1) Disconnect the negative battery terminal.

AC801404

AJ

Connector: C-154

C-154 (Y)

Harness side 
connector 
(rear view)

(2) Disconnect SRS-ECU connector C-154.

CAUTION

Do not insert a test probe into the terminal from 
its front side directly as the connector contact 
pressure may be weakened.

AC800962 BX

C-154 Harness side 
connector (rear view)

AC800962 BY

C-154 Harness side 
connector (rear view)

(3) Take the measurements below at harness side 

B1600

Left front impact sensor or wiring open circuit

B1601

Short to body earth in the left front impact sensor harness

B1602

Short to the power supply in the left front impact sensor harness

Code No.

Trouble causes

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-225

connector C-154.

• Resistance between terminals 29 and 30 as 

well as 35 and 36.

OK: 820 

± 82 Ω

AC800962 BZ

C-154 Harness side 
connector (rear view)

• Continuity between terminals 29, 30, 35, 36 

and body earth

OK: Open circuit

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

 Repair the harness wire between the front 
impact sensor (RH) connector A-124 
(terminals 1 and 2) and SRS-ECU 
connector C-154 (terminals 36 and 35) as 
well as between front impact sensor (LH) 
connector A-30 (terminals 1 and 2) and 
SRS-ECU connector C-154 (terminals 29 
and 30).

STEP 3. Voltage measurement at the SRS-ECU 
connector C-154.
(1) Disconnect the negative battery terminal.

AC801404

AJ

Connector: C-154

C-154 (Y)

Harness side 
connector 
(rear view)

(2) Disconnect SRS-ECU connector C-154.

(3) Connect the negative battery terminal.
(4) Turn the ignition switch to the "ON" position.

AC800963AV

C-154 Harness side 
connector (rear view)

CAUTION

Do not insert a test probe into the terminal from 
its front side directly as the connector contact 
pressure may be weakened.
(5) Take the measurements below at harness-side 

connector C-154.

• Voltage between terminals 29, 30, 35, 36 and 

body earth

OK: 1 V or less

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

 Repair the harness wire between the front 
impact sensor (RH) connector A-124 
(terminals 1 and 2) and SRS-ECU 
connector C-154 (terminals 36 and 35) as 
well as between front impact sensor (LH) 
connector A-30 (terminals 1 and 2) and 
SRS-ECU connector C-154 (terminals 29 
and 30).

STEP 4. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set.

Q: Is diagnosis code B1595, B1596, B1597, B1598, 

B1599, B1600, B1601 or B1602 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 ).

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-226

Code No.B1603: Seat belt pre-tensioner (driver's side) (squib) system (short-circuited between 
terminals of the squib circuit) 

AC806068

Seat Belt Pre-tensioner (Driver's Side)  (Squib)

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR COUPLED: ON 
  CONNECTOR UNCOUPLED: OFF

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

AB

SEAT BELT 
PRE-TENSIONER 

<LHD>
<RHD>

OPERATION
The SRS-ECU judges how severe a collision is by 
detecting signals from the front impact sensors and 
the front air bag analogue G-sensor. If the impact is 
over a predetermined level, the SRS-ECU sends an 
ignition signal. At this time, if the front air bag safing 
G-sensor is on, the seat belt pre-tensioner will 
deploy. 

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if one seat belt pre-ten-
sioner (driver's side) squib wire shorted to the other.

PROBABLE CAUSES

• Improper engaged connector or defective short 

spring*

• Short circuit between the seat belt pre-tensioner 

(driver's side) (squib) circuit terminals

• Damaged connector(s)

• Malfunction of the SRS-ECU

NOTE: *: The squib circuit connectors integrate a 
"short" spring (which prevents the air bag from 
deploying unintentionally due to static electricity by 
shorting the positive wire to the earth wire in the 
squib circuit when the connectors are disconnected). 
Therefore, if connector C-155 or D-15 <LHD> or D-
23 <RHD> is damaged or improperly engaged, the 
short spring may not be released when the connector 
is connected.

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code.

Q: Is diagnosis code B1519 set?

YES : 

Go to Step 2.

NO : 

Go to Step 3.