Mitsubishi Galant (2004+). Manual - part 1548

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-85

STEP 3. Using scan tool MB991958, read the diagnostic 
trouble code.

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) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOOK (OFF)" position.
Q: Is DTC B1519 set?

YES : Go to Step 4.
NO :  Go to Step 5.

STEP 4. Check SRS-ECU connector C-121.

Q: Is the connector correctly engaged?

YES : Go to Step 5.
NO :  Engage the connector correctly. Then go to Step 9.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305362

CONNECTOR: C-121

C-121 (Y)

AH

SRS-ECU

C-121
HARNESS SIDE 
CONNECTOR
(REAR VIEW)

42

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B

A

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-86

STEP 5. Check SRS-ECU connector C-121 and passenger’s 
air bag module connector C-110. (Using scan tool 
MB991958, read the diagnostic trouble code.)

(1) Disconnect the negative battery terminal.
(2) Disconnect connectors C-121 and C-110, and then 

reconnect them.

(3) Slide the outer housing of the clock spring side of driver’s 

air bag module connector C-110 in the arrow direction 
shown, and disconnect the connector.

(4) Connect the negative battery terminal.
(5) Erase the diagnostic trouble code memory, and check the 

diagnostic trouble code.

Q: Is DTC B1410 <1st squib> or B1490 <2nd squib> set?

YES : Go to Step 6.
NO :  The procedure is complete. It is assumed that DTC 

B1410 <1st squib> or B1490 <2nd squib> set as 
connector C-121 or C-110 was engaged improperly.

AC307137AC

C-110 (Y)

FRONT DECK
CROSSMEMBER

CONNECTOR: C-110

HARNESS SIDE 
CONNECTOR
(REAR VIEW)

AC305362

CONNECTOR: C-121

C-121 (Y)

AH

SRS-ECU

C-121
HARNESS SIDE 
CONNECTOR
(REAR VIEW)

42

31

38

27

21

41

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47

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B

A

AC306561AD

OUTER HOUSING OF THE PASSENGER'S 
AIR BAG MODULE CONNECTOR C-110

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-87

STEP 6. Check the passenger's air bag module. (Using 
scan tool MB991958, read the diagnostic trouble code.)

(1) Disconnect the negative battery terminal.
(2) Disconnect the passenger’s air bag module connector 

C-110.

(3) Slide the outer housing of the clock spring side of 

passenger’s air bag module connector C-110 in the arrow 
direction shown, and disconnect the connector.

(4) Connect special tool MB991865 to special tool MB991866.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly as the connector contact pressure may be 
weakened.
(5) Insert special tool MB991866 into the harness side 

connector C-110 (terminal No.1 and 2 <1st squib> or 
terminal No.3 and 4 <2nd squib>) by backprobing.

(6) Connect the negative battery terminal.
(7) Erase the diagnostic trouble code memory, and check the 

diagnostic trouble code.

Q: Is DTC B1410 <1st squib> or B1490 <2nd squib> set?

YES : Go to Step 7.
NO :  Replace the passenger's air bag module (Refer to 

P.52B-368

). Then go to Step 9. 

AC307137AC

C-110 (Y)

FRONT DECK
CROSSMEMBER

CONNECTOR: C-110

HARNESS SIDE 
CONNECTOR
(REAR VIEW)

AC306561AD

OUTER HOUSING OF THE PASSENGER'S 
AIR BAG MODULE CONNECTOR C-110

AC306760AB

MB991865 (DUMMY 
RESISTOR: 3 

Ω)

MB991866
(RESISTOR HARNESS)

C-110 HARNESS 
CONNECTOR

C-110
PASSENGER'S
AIR BAG MODULE 
CONNECTOR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-88

STEP 7. Check the passenger’s air bag module circuit at 
SRS-ECU connector C-121.

(1) Disconnect SRS-ECU connector C-121.

DANGER

To prevent the air bag from deploying unintentionally, 
disconnect the passenger’s air bag module connec-
tor C-110 to short the squib circuit.

(2) Disconnect the passenger's air bag module connector 

C-110.

(3) Slide the outer housing of the clock spring side of driver’s 

air bag module connector C-110 in the arrow direction 
shown, and disconnect the connector.

AC305362

CONNECTOR: C-121

C-121 (Y)

AH

SRS-ECU

C-121
HARNESS SIDE 
CONNECTOR
(REAR VIEW)

42

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38

27

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B

A

AC307137AC

C-110 (Y)

FRONT DECK
CROSSMEMBER

CONNECTOR: C-110

HARNESS SIDE 
CONNECTOR
(REAR VIEW)

AC306561AD

OUTER HOUSING OF THE PASSENGER'S 
AIR BAG MODULE CONNECTOR C-110