Mitsubishi Outlander GS45X. Manual - part 1464

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-351

CAUTION

If DTC B1B79, B1B7E, B1B83 or B1B88 is set in 
the occupant classification-ECU, always diag-
nose the CAN main bus lines.

.

CIRCUIT OPERATION

The load data from the weight sensor is classified 
with the occupant classification-ECU, and its classi-
fied information is send to SRS-ECU by CAN bus 
line. The SRS-ECU determines the air bag deploy-
ment based on this classified information, and con-
trols the power supply circuit to the inflator. 

.

DTC SET CONDITIONS

This DTC is see if the weight sensor wire are 
short-circuited to the ground.

.

TROUBLESHOOTING HINTS

• Disengaged wire harnesses or connector

• Short to the ground in the weight sensor harness

• Malfunction of the weight sensor

• Malfunction of the occupant classification-ECU

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A (Vehicles with 

CAN Communication System)

AC901079

Connectors: D-34-1

AM

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-352

STEP 1. Using scan tool MB991958, diagnose the CAN bus 
line.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the 

scan tool 

P.52B-28

."

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO :  Repair the CAN bus line (Refer to GROUP 54C, 

Diagnosis 

P.54C-17

).

STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Go to Step 3.
NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Cope with Intermittent 
Malfunction 

P.00-15

).

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-353

STEP 3. Measure the resistance at occupant 
classification-ECU connector D-34-1.
(1) Disconnect the connector D-34-1.
(2) Disconnect weight sensor connector D-34-3, D-34-4, 

D-34-5 or D-34-6.

(3) Check for continuity between D-34-1 harness side 

connector terminals 1, 3, 5, 7, 9 and body ground.
It should be open circuit.

Q: Is it open circuit? 

YES : Go to Step 4.
NO :  Repair the wiring harness between occupant 

classification-ECU connector D-34-1 terminals 3, 5, 9, 
7 and weight sensor connector D-34-3, 4, 5, 6 
terminals 3 (signal line) or occupant 
classification-ECU connector D-34-1 terminals 1 and 
weight sensor connector D-34-3 terminals 2 (power 
supply line). Then go to Step 4.

STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTCs B1B79, B1B7E, B1B83, B1B88 set?

YES : Replace the passenger seat cushion frame assembly 

(Refer to GROUP 52A, Front Seat Assembly 

P.52A-17

).

NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Cope with Intermittent 
Malfunction 

P.00-15

).

AC608812DP

D-34-1 Harness side 
connector (front view)

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-354

DTC B1B7A: Passenger Seat Weight Sensor (power supply side) Short-circuited or Open (front: LH)

 

DTC B1B7F: Passenger Seat Weight Sensor (power supply side) Short-circuited or Open (front: RH)

 

DTC B1B84: Passenger Seat Weight Sensor (power supply side) Short-circuited or Open (rear: LH)

 

DTC B1B89: Passenger Seat Weight Sensor (power supply side) Short-circuited or Open (rear: RH)

AC803887

OCCUPANT 
CLASSIFICATION-
ECU

FRONT SEAT 
ASSEMBLY (RH)

WEIGHT SENSOR 
(FRONT: LH)

WEIGHT SENSOR 
(FRONT: RH)

WEIGHT SENSOR 
(REAR: LH)

WEIGHT SENSOR 
(REAR: RH)

AB