Mitsubishi Evolution X. Manual - part 671

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-131

STEP 3. Check by dummy resistor connection.
(1) Disconnect the negative battery terminal.
(2) Disconnect the D-15 intermediate connector (connection

between curtain air bag harness and floor harness).

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

CAUTION

Do not insert a probe into the terminal from its front side
directly, as the connector contact pressure may be weak-
ened.
(4) Insert the probe of resistor harness, to which the dummy

resistor is installed, from the back of D-15 intermediate
connector (floor harness side).

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

diagnostic trouble code again.

(7) Disconnect the negative battery terminal.
Q: Is DTC B1B1A set?

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

AC507310

D-15 Intermediate connector
(Curtain air bag harness side)

D-15
Intermediate
connector
(Floor harness side)

MB991865
(Dummy resistor: 3 )

MB991866

(Resistor harness)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-132

STEP 4. Resistance measurement at the C-36 SRS-ECU
connector and the D-15 intermediate connector.
(1) Disconnect the negative battery terminal.
(2) 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.

DANGER

To prevent the air bag from deploying unintentionally,
disconnect the intermediate connector D-15 to short
the squib circuit.

(3) Disconnect the D-15 intermediate connector (connection

between curtain air bag harness and floor harness).

CAUTION

The short spring may not be released due to the insuffi-
cient insertion. Therefore, insert the insulator for 4 mm (0.6
inch) or more.
(4) Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch)

thick] between terminal 41, 42 and the short spring to
release the short spring.

CAUTION

Do not insert a probe into the terminal from D-15 interme-
diate connector front side directly, as the connector con-
tact 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.41) and the

intermediate connector D-15 (terminal No.1)

• SRS-ECU connector C-36 (terminal No.42) and the

intermediate connector D-15 (terminal No.2)

Q: Does continuity exist?

YES : Go to Step 6.
NO : Repair the wiring harness between the C-36 harness

side connector terminal No. 41, 42 and the D-15
intermediate connector (floor harness side) terminal
No. 1, 2.

AC507645

Lock lever

AC507303 BY

C-36 Harness side
connector (front view)

Section
A - A

Cable tie

Short spring

4 mm (0.16 inch) or more

Terminal

AC608812FP

C-36 Harness side
connector (front view)

D-15 Intermediate connector
(Curtain air bag harness side)
(rear view)

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-133

STEP 5. Resistance measurement at the D-15 intermediate
connector terminal No. 1, 2 and the F-28 curtain air bag
module harness side connector terminal No. 1, 2.
(1) Disconnect the negative battery terminal.

DANGER

To prevent the air bag from deploying unintentionally,
disconnect the curtain air bag module connector F-28
to short the squib circuit.

(2) Disconnect curtain air bag module (LH) F-28. 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) Disconnect the D-15 intermediate connector (connection

between curtain air bag harness and floor harness).

(4) Because the short spring is installed to the D-15

intermediate connector (curtain air bag harness side), insert
a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick]
between terminals 1, 2 and the short spring to release the
short spring.

(5) Connect special tool MB991884 to the removed F-28

harness side connector.

CAUTION

Do not insert a probe into the terminal from D-15 interme-
diate connector front side directly, as the connector con-
tact pressure may be weakened.
(6) Check for continuity between the following terminals. It

should be less than 2 ohms.

• Intermediate connector D-15 (terminal No.1) and resis-

tor harness connector terminal No.2)

• Intermediate connector D-15 (terminal No.2) and resis-

tor harness connector terminal No.1)

Q: Does continuity exist?

YES : Replace the curtain air bag module (squib) (Refer to

P.52B-409

AC609928AB

Locking
button

Flat-tipped
screwdriver

Inflator

Curtain air bag wiring
harness connector

AC700119

D-15 Intermediate
connector (module side )

22 mm or more

Cable tie

Short spring

AC201287DK

F-24 Harness side
connector

MB991884

AC608812FQ

Resistor
harness
connector

D-15 Intermediate connector
(Curtain air bag harness side)
(rear view)

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-134

NO : Repair the wiring harness.

STEP 6. 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 B1B1A set?

YES : Replace SRS-ECU (Refer to

P.52B-383

NO : Intermittent Malfunction (Refer to GROUP 00, How to

Use Troubleshooting/Inspection Service Points

− How

to Cope with Intermittent Malfunction

P.00-15

DTC B1B1B: Curtain Air Bag Module (LH) (Squib) System (Short Circuit between Squib Circuit
Terminals)

CURTAIN AIR BAG
MODULE (SQUIB) (LH)

CONNECTOR
LOCK
SWITCH

SRS-ECU

NOTE

: CONNECTOR COUPLED : ON

CONNECTOR UNCOUPLED : OFF

Curtain Air Bag Module (Squib) (LH) Circuit

CONNECTOR
LOCK SWITCH

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