Mitsubishi Evolution X. Manual - part 690

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-207

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 33, 34 and the short spring to
release the short spring.

CAUTION

Do not insert a test probe into the terminal from D-36 har-
ness side connector front side directly, as the connector
contact pressure may be weakened.
(5) Check for continuity between the following terminals. It

should be less than 2 ohms.

• SRS-ECU connector C-36 (terminal No.33) and the

side-air bag module (RH) connector D-36 (terminal
No.1)

• SRS-ECU connector C-36 (terminal No.34) and the

side-air bag module (RH) connector D-36 (terminal
No.2)

Q: Does continuity exist?

YES : Erase the diagnostic trouble code memory, and check

the diagnostic trouble code. If DTC B1C2D sets,
replace the SRS-ECU (Refer to

P.52B-383

). Then go

to Step 5.

NO : Replace the harness wires between SRS-ECU

connector C-36 and side-air bag module (RH)
connector D-36. Then go to Step 5.

STEP 5. 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 B1C2D set?

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

AC507303 CB

C-36 Harness side
connector (front view)

Section
A - A

Cable tie

Short spring

4 mm (0.16 inch) or more

Terminal

AC608812

D-36 Harness side
connector
(rear view)

C-36 Harness side
connector (front view)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-208

DTC B1C2E: Side-air bag Module (RH) (Squib) System (Short Circuit between Squib Circuit Terminals)

CAUTION

If DTC B1C2E is set in the SRS-ECU, always diag-
nose the CAN bus lines.

CIRCUIT OPERATION

• The SRS-ECU judges how severe a collision is

by detecting signals from the side impact sensor
installed on the lower side of the center pillar. If
the impact is over a predetermined level, the
SRS-ECU sends an ignition signal. At this time, if
the side collision safing G-sensor is on, the SRS
air bag will inflate.

• The ignition signal is input to the side-air bag

module to inflate the side-air bag.

DTC SET CONDITIONS

This DTC is set if there is abnormal resistance
between the input terminals of the side-air bag mod-
ule (RH) (squib).

TROUBLESHOOTING HINTS

• Improper engaged connector or defective short

spring*

• Short between the side-air bag module (RH)

(squib) circuit terminals

• Damaged connector(s)

• Malfunction of the SRS-ECU

NOTE

: CONNECTOR COUPLED : ON

CONNECTOR UNCOUPLED : OFF

SIDE-AIR BAG MODULE
(SQUIB) (RH)

CONNECTOR
LOCK
SWITCH

CONNECTOR
LOCK SWITCH

SRS-ECU

Side-airbag Module (Squib) (RH) Circuit

AC708951AD

Connector: C-36

C-36 (Y)

AC708954 AF

Connector: D-36

D-36 (Y)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-209

NOTE: *: The squib circuit connectors integrate a
"short" spring (which prevents the air bag from
deploying unintentionally due to static electricity by
shorting the positive wire to the ground wire in the
squib circuit when the connectors are disconnected)
(Refer to

P.52B-3

). Therefore, if connector C-36 or

D-36 is damaged or improperly engaged, the short
spring may not be released when the connector is
connected.

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)

• MB991865: Dummy resister

• MB991866: Resister harness

STEP 1. Using scan tool MB991934, diagnose the CAN bus
line.

CAUTION

To prevent damage to scan tool MB991934, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991934.
(1) Connect scan tool MB991934. Refer to "How to connect the

scan tool

P.52B-28

(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,

Diagnosis

P.54C-14

AC608435

Data link connector

MB991827

MB991824

MB991910

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-210

STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC 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

STEP 3. Check SRS-ECU connector C-36 and side-air bag
module (RH) connector D-36.
(1) Disconnect the negative battery terminal.
(2) Disconnect connectors D-36, and then reconnect them.
(3) While pushing the part "A" indicated in the figure of the

harness side connector, turn the lock lever to the direction
of the arrow to release the lock lever, and disconnect the
C-36 SRS-ECU connector. Then connect the connector.

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

diagnostic trouble code.

Q: Is DTC B1C2E out put?

YES : Go to Step 4.
NO : The procedure is complete. It is assumed that DTC

B1C2E set because connector C-36 or D-36 was
engaged improperly.

STEP 4. Check the side-air bag module (RH).
(1) Disconnect the negative battery terminal.
(2) Disconnect the side-air bag module (RH) connector D-36.
(3) 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.
(4) Insert special tool MB991866 into the D-36 harness side

connector by backprobing.

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

diagnostic trouble code.

Q: Is DTC B1C2E set?

YES : Go to Step 5.
NO : Replace the front seatback (Refer to GROUP 52A,

Front Seat Assembly

P.52A-24

). Then go to Step 7.

AC609027

Lock lever

AC507310 AX

D-36

Side-airbag

module (RH) connector

D-36
Harness side
connector

MB991865
(Dummy resistor: 3 )

MB991866

(Resistor harness)

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