Mitsubishi Outlander GS45X. Manual - part 1465

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-355

CAUTION

If DTC B1B7A, B1B7F, B1B84 or B1B89 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 set if the weight sensor wire are

short-circuited to the power supply.

• This DTC is set if the weight sensor wire are open

circuit

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors

• Short to the power supply in the weight sensor harness

• Open circuit 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, D-34-3, D-34-4, D-34-5,
D-34-6

D-34-1, D-34-3,
D-34-4, D-34-5,
D-34-6

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-356

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 DTCs 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-357

STEP 3. Measure the voltage 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) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminals 1, 3, 5, 7, 9 and

body ground.
Voltage should measure 1 volt or less.

Q: Is the measured voltage within the specified range?

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.

AC608813 CK

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

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-358

STEP 4. Check the harness open circuit between occupant
classification-ECU connector D-34-1 and weight sensor
connector D-34-3, D-34-4, D-34-5 or D-34-6.
(1) Disconnect occupant classification-ECU connector D-34-1

and weight sensor connector D-34-3, D-34-4, D-34-5 or
D-34-6.

(2) Check for continuity between the following terminals.

It should be less than 2 ohms.