Mitsubishi Outlander GS45X. Manual - part 1466

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-359

DTC B1B8C: Driver Seat Slide Sensor Circuit Performance

CAUTION

If DTC B1B8C is set in the occupant classifica-
tion-ECU, always diagnose the CAN main bus 
lines.

.

CIRCUIT OPERATION

• The seat slide sensor sets the current value Hi or 

Low determined by the seat position.

• The occupant classification-ECU determines the 

seat position according to the current value from 
the seat slide sensor.

.

DTC SET CONDITION

The DTC is set when the seat slide sensor output 
current is not within the specified range.

.

TROUBLESHOOTING HINTS

• The seat slide sensor may be defective.

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

• Malfunction of the occupant classification-ECU

D7G52M031A00

AC701825

HALL IC

Seat Slide Sensor Circuit

OCCUPANT 
CLASSIFICATION-
ECU

FRONT SEAT 
ASSEMBLY (RH)

SEAT SLIDE 
SENSOR

AB

AC901079

Connectors: D-27, D-34, D-34-2

AN

D-34, 
D-34-2

D-27 (GR)

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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)

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

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

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STEP 3. Check the occupant classification-ECU connector 
D-34-2, front seat assembly connector D-34 and seat slide 
sensor connector D-27 for loose, corroded or damaged 
terminals, or terminals pushed back in the connector.
Q: Is the occupant classification-ECU connector D-34-2, 

front seat assembly connector D-34 and seat slide 
sensor connector D-27 in good condition?
YES : Go to Step 4.
NO :  Replace the component(s) (Refer to GROUP 00E, 

Harness Connector Inspection 

P.00E-2

).

STEP 4. Check the harness for open circuit between 
occupant classification-ECU connector D-34-2 (terminal 
No.27 and 29) and the seat slide sensor connector D-27 
(terminal No.2 and 1).
(1) Disconnect occupant classification-ECU connector D-34-2 

and seat slide sensor connector D-27.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(2) Check for continuity between the following terminals. It 

should be less than 2 ohms.

• Occupant classification-ECU connector D-34-2 (terminal 

No.27) and the seat slide sensor connector D-27 (termi-
nal No.2)

• Occupant classification-ECU connector D-34-2 (terminal 

No.29) and the seat slide sensor connector D-27 (termi-
nal No.1)

Q: Does continuity exist?

YES : Go to Step 5.
NO :  Repair the harness wires between occupant 

classification-ECU connector D-34-2 and seat slide 
sensor connector D-27.

AC608812

D-27 Harness side 
connector (rear view)

IY

D-34-2 Harness side 
connector (

rear

 view)

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

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STEP 5. Check the seat slide sensor circuit. Measure the 
resistance at occupant classification-ECU connector 
D-34-2.
(1) Disconnect occupant classification connector-ECU 

connector D-34-2.

(2) Disconnect seat slide sensor connector D-27.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(3) Check for continuity between D-34-2 harness side 

connector terminals 27 and 29.
It should be open circuit.

Q: Is it open circuit?

YES : Go to Step 6.
NO :  Repair the harness wires between occupant 

classification-ECU connector D-34-2 and seat slide 
sensor connector D-27.

STEP 6. Check the harness for open circuit between 
occupant classification-ECU connector D-34-2.
(1) Disconnect occupant classification-ECU connector D-34-2 

and seat slide sensor connector D-27.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(2) Check for continuity between D-34-2 Occupant 

classification-ECU connector terminals No.27, 29 and body 
ground.
It should be open circuit.

Q: Is it open circuit?

YES : Go to Step 7
NO :  Repair the harness wires between occupant 

classification-ECU connector D-34-2 and seat slide 
sensor connector D-27.

AC608812IX

D-34-2 Harness side 
connector (

rear

 view)

AC608812IZ

D-34-2 Harness side 
connector (

rear

 view)