Mitsubishi Galant (2004+). Manual - part 1549

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-89

CAUTION

Insert an insulator such as a cable tie to a depth of 4mm 
(0.16 inch) or more, otherwise the short spring will not be 
released.
(4) Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) 

thick] between terminals 27 and 28 <1st squib> or 30 and 

31 <2nd squib>, and the short spring to release the short 
springr.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly as the connector contact pressure may be 
weakened.
(5) Check for continuity between C-121 harness side connector 

terminals 27 and 28 <1st squib> or 30 and 31 <2nd squib>.

It should be open circuit.

Q: Does continuity exist?

YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1410 <1st 
squib> or B1490 <2nd squib> set, replace the 
SRS-ECU. (Refer to 

P.52B-365

). Then go to Step 9.

NO :  Go to Step 8. 

AC308142

SECTION
A - A

C-121 HARNESS SIDE 
CONNECTOR
(FRONT VIEW)

CABLE TIE

SHORT SPRING

4 mm OR MORE

TERMINAL

AB

<1ST SQUIB>

A

A

AC308143

SECTION
A - A

C-121 HARNESS SIDE 
CONNECTOR
(FRONT VIEW)

CABLE TIE

SHORT SPRING

4 mm OR MORE

TERMINAL

AB

<2ND SQUIB>

A

A

AC301582

42

31

38

27

21

41

28

39

22

30

25

47

36

33

44

34

45

37

48

26

29

23

40

32

43

35

46

24

B

A

C-121 HARNESS SIDE 
CONNECTOR (REAR VIEW)

<1ST SQUIB>

AC

AC308150

42

31

38

27

21

41

28

39

22

30

25

47

36

33

44

34

45

37

48

26

29

23

40

32

43

35

46

24

B

A

C-121 HARNESS SIDE 
CONNECTOR (REAR VIEW)

<2ND SQUIB>

AB

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-90

STEP 8. Check the harness for short circuit between 
SRS-ECU connector C-121 (terminal No.27 and 28 <1st 
squib> or terminal No.30 and 31 <2nd squib>) and 
passenger's air bag module connector C-110 (terminal 
No.1 and 2 <1st squib> terminal No.4 and 3 <2nd squib>).

NOTE: After inspecting intermediate connector C-22 inspect 
the wiring harness. If the intermediate connector C-22 is dam-
aged, repair or replace it.
Q: Are harness wires between SRS-ECU connector C-121 

(terminal No.27 and 28 <1st squib> or terminal No.30 
and 31 <2nd squib>) and passenger's air bag module 
connector C-110 (terminal No.1 and 2 <1st squib> 
terminal No.4 and 3 <2nd squib>) in good condition?
YES : Go to Step 9.
NO :  Replace the harness wires between SRS-ECU 

connector C-121 and passenger’s air bag module 
connector C-110. Then go to Step 9.

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

28

39

22

30

25

47

36

33

44

34

45

37

48

26

29

23

40

32

43

35

46

24

B

A

AC305233

C-22 (Y)

CO

CONNECTOR: C-22

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-91

STEP 9. Check 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 DTC B1410 <1st squib> or B1490 <2nd squib> set?

YES : Return to Step 1.
NO :  The procedure is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-92

DTC B1411: Passenger’s (Front) Air Bag Module (1st Squib) System Fault 2 (Open in the Squib 
Circuit)
DTC B1491: Passenger’s (Front) Air Bag Module (2nd Squib) System Fault 2 (Open in the Squib 
Circuit)

AIR BAG MODULE 
(SQUIB) 
(PASSENGER'S SIDE)

AIR BAG DRIVE CIRCUIT

SRS-ECU

CONNECTOR
LOCK SWITCH

Passenger's (Front) Air Bag Module (1st Squib and 2nd Squib) Circuit

NOTE
  : CONNECTOR CONNECTED
    : ON
    CONNECTOR DISCONNECTED
    : OFF

AC305233 AO

CONNECTOR: C-22

C-22 (Y)

AC307137AD

C-110 (Y)

FRONT DECK
CROSSMEMBER

CONNECTOR: C-110