Mitsubishi Galant 9G. Manual — part 1458

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-242

STEP 7. Check the SRS-ECU power supply circuit for short
circuit to ground. Measure the resistance at the junction
block connector C-211.
(1) Disconnect junction block connector C-211, and measure at

the wiring harness side.

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 terminal 7 <DTC B1476> or

24 <DTC B1477> and body ground.
It should be open circuit.

Q: Does continuity exist?

YES : Check the other circuit, which flows through fuse

No.22 <DTC B1476> or fuse No.23 <DTC
B1477>.Then go to Step 10.

NO : Go to Step 8.

STEP 8. Check the power supply circuit for short circuit to
ground. Measure the resistance at the SRS-ECU connector
C-121.
(1) Disconnect SRS-ECU connector C-121, and measure at

the wiring harness side.

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 terminal 23 <DTC B1476> or

24 <DTC B1477> and body ground.
It should be open circuit.

Q: Does continuity exist?

YES : Go to Step 9.
NO : Erase the diagnostic trouble code memory, and check

the diagnostic trouble code. If DTC B1476 or B1477
sets, replace the SRS-ECU (Refer to

P.52B-365

).

Then go to Step 10.

AC305415AN

CONNECTOR: C-211

AC308200

1 2 3 4 5 6 7 8 9 10 1112 1314

1516 1718 19 20 212223 242526 2728

C-211 HARNESS SIDE
CONNECTOR (REAR VIEW)

AB

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

AC308195

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)

AB

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-243

STEP 9. Check the harness for short circuit to ground
between SRS-ECU connector C-121 (terminal No.23 <DTC
B1476> or terminal No.24 <DTC B1477>) and junction
block connector C-211 (terminal No.7 <DTC B1476> or
terminal No.24 <DTC B1477> ).

NOTE: After inspecting intermediate connector C-22, inspect
the wiring harness. If intermediate connectors are damaged,
repair or replace them. Refer to GROUP 00E, Harness Con-
nector Inspection . Then go to Step 10.

Q: Is the harness wire between SRS-ECU connector C-121

(terminal No.23 <DTC B1476> or terminal No.24 <DTC
B1477>) and junction block connector C-211 (terminal
No.7 <DTC B1476> or 24 <DTC B1477>) in good
condition?
YES : Go to Step 10.
NO : Replace the harness wire between SRS-ECU

connector C-121 and junction block connector C-211.
Then go to Step 10.

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

AC305415AH

CONNECTOR: C-211

C-211

HARNESS SIDE

JUNCTION BLOCK

(FRONT VIEW)

AC305233 AI

CONNECTOR: C-22

C-22 (Y)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-244

STEP 10. 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 DTC B1476 or DTC B1477 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-245

DTC B1486: Passenger’s seat belt warning Light Drive Circuit System Fault 2.

CAUTION

If DTC B1486 is set in the SRS-ECU, always diag-
nose the CAN main bus line.

.

CIRCUIT OPERATION

• Power for the passenger’s seat belt warning light

is supplied from the ignition switch (IG1).

• The passenger’s seat belt warning light illumi-

nates when the ignition switch is turned to the
"ON" position and goes out after approximately
seven seconds if there is not a malfunction in the
SRS system.

.

Seat Belt Warning Light Drive Circuit

SRS-ECU

IGNITION
SWITCH (IG1)

JUNCTION
BLOCK

SEAT BELT
WARNING
LIGHT
(PASSEGER'S SIDE)

RELAY
BOX

JOINT
CONNECTOR (1)

TAILLIGHT
RELAY

FRONT ECU

JUNCTION
BLOCK

SEAT BELT
WARNING LIGHT
DRIVE CIRCUIT