Mitsubishi Grandis. Manual — part 1012

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-100

stages, and then disconnect the connector.

(2) Connect G-04 harness side connector to special

tool resistor harness (MB991884).

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(3) Resistance measurement between the following

terminals.

• SRS-ECU connector C-118 terminal No.62

and special tool terminal No.1

• SRS-ECU connector C-118 terminal No.61

and special tool terminal No.2

OK: Less than 2

Ω

Q: Are the check results normal?

YES :

Go to Step 5.

NO :

Repair the harness wire between SRS-ECU
connector C-118 (terminal No.61and 62)
and curtain air bag module (RH) connector
G-04 (terminal No.1 and 2).

STEP 5. Check whether the diagnosis code is
reset.

Q: Is diagnosis code No.B1441 set?

YES :

Replace the SRS-ECU (Refer to

P.52B-223

).

NO :

An intermittent malfunction is suspected
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-5

).

AC201287BI

G-04

Harness side
connector

MB991884

AC301555

2

1

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

AC

<G-04 Harness
connector>
Special tool
MB991884
(front view)

C-118
Harness side
connector
(rear view)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-101

Code No.B1442: Curtain air bag module (squib) (RH) system (short-circuited to the earth)

CAUTION

If diagnosis code B1442 is set in the SRS-ECU,
always diagnose the CAN main bus line.

OPERATION

The SRS-ECU judges how severe a collision is by
detecting signals from the side impact sensors and
the side air bag safing G-sensor. If the impact is over
a predetermined level, the SRS-ECU outputs an
ignition signal. At this time, if the side air bag safing
G-sensor is on, the curtain air bag module will
deploy.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set if the curtain air bag
module squib (RH) wire(s) are short-circuited to the
earth.

PROBABLE CAUSES

• Damaged wiring harnesses or connectors

• Short to the earth in the curtain air bag module

(squib) (RH) harness

• Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. MUT-III CAN bus diagnostics

Use the MUT-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN bus line (Refer to GROUP
54D, Diagnosis

P.54D-16

).

STEP 2. Check whether the diagnosis code is
reset.

Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is

not reset.

Q: Is the diagnosis code 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.00-5

).

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

: CONNECTOR
CONNECTED: ON
CONNECTOR
DISCONNECTED: OFF

NOTE

CURTAIN AIR BAG
MODULE
(SQUIB) (RH)

Curtain Air Bag Module (Squib) (RH) Circuit

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-102

STEP 3. Check the curtain air bag module (RH).
(MUT-III diagnosis code.)
(1) Disconnect the negative battery terminal.

(2) Disconnect curtain air bag module connector

G-04. Use a flat-tipped screwdriver to unlock the
locking button at the harness side connector by
withdrawing it toward you in two stages, and then
disconnect the connector.

(3) Connect special tool dummy resistor (MB991865)

to special tool resistor harness (MB991884).

(4) Connect special tool (MB991884) to the G-04

harness side connector.

(5) Connect the negative battery terminal.
(6) Erase diagnosis code memory, and check the

diagnosis code.

Q: Is diagnosis code B1442 set?

YES :

Go to Step 4.

NO :

Replace the curtain air bag module (RH)
(Refer to

P.52B-231

).

STEP 4. Check the curtain air bag module (RH)
circuit. Resistance measurement at the SRS-ECU
connector C-118.

(1) Disconnect SRS-ECU connector C-118.

(2) Disconnect curtain air bag module connector

G-04. Use a flat-tipped screwdriver to unlock the
locking button at the harness side connector by
withdrawing it toward you in two stages, and then

AC302575AD

G-04 (B)

Connector: G-04

Harness side
(front view)

Roof centre duct

AC208384AM

G-04
Curtain air bag
module connector

Flat-tip screw
driver

Locking button

G-04
Harness side
connector

AC301553AI

MB991865
(Dummy resistor : 3

ΩΩ

MB991884
(Resistor
harness)

G-04 Harness side connector

AC311438 AC

C-118 (Y)

Connector: C-118

Harness side
(front view)

AC302575AD

G-04 (B)

Connector: G-04

Harness side
(front view)

Roof centre duct

AC208384AM

G-04
Curtain air bag
module connector

Flat-tip screw
driver

Locking button

G-04
Harness side
connector

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-103

disconnect the connector.

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(3) Resistance measurement between C-118

harness side connector terminals 61, 62 and

body earth.

OK: Open circuit

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the harness wire between SRS-ECU
connector C-118 (terminal No.61and 62)
and curtain air bag module (RH) connector
G-04 (terminal No.1 and 2).

STEP 5. Check whether the diagnosis code is
reset.

Q: Is diagnosis code B1442 set?

YES :

Replace the SRS-ECU (Refer

to

P.52B-223

).

NO :

An intermittent malfunction is suspected
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-5

).

Code No.B1443: Curtain air bag module (squib) (RH) system (short-circuited to the power supply)

AC301575

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

C-118
Harness side connector
(rear view)

AC

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

: CONNECTOR
CONNECTED: ON
CONNECTOR
DISCONNECTED: OFF

NOTE

CURTAIN AIR BAG
MODULE
(SQUIB) (RH)

Curtain Air Bag Module (Squib) (RH) Circuit