Mitsubishi Outlander XL. Manual — part 896

DTC B1B20: Curtain Air Bag Module (RH) (Squib) System (Shorted to Squib Circuit
Ground)

M15204000960USA0000010000

: CONNECTOR LOCK SWITCH
CONNECTOR COUPLED : ON
CONNECTOR UNCOUPLED : OFF

NOTE

CURTAIN AIR BAG
MODULE
(SQUIB) (RH)

SRS-ECU

Curtain Air Bag Module (Squib) (RH) Circuit

ZC600876

Connector: C-27

C-27 (Y)

0025

ZC600880

Connectors: D-08, D-104

D-104 (B)

D-08 (Y)

0012

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-115

SRS AIR BAG DIAGNOSIS

If DTC B1B20 is set in the SRS-ECU, always
diagnose the CAN main bus line.

CIRCUIT OPERATION

｠

The SRS-ECU judges how severe a collision is by
detecting signals from the side impact sensors
installed on the lower side of the center pillar and at
the quarter panel inner. If the impact is over a
predetermined level, the SRS-ECU sends an
ignition signal. At this time, if the side-airbag safing
G-sensor is on, the SRS side-airbag will inflate.

｠

The ignition signal is input to the curtain air bag
module (RH) to inflate the curtain air bag.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance
between the input terminals of the curtain air bag
module (RH) (squib).

TROUBLESHOOTING HITS

｠

Damaged wiring harnesses or connectors

｠

Short to the ground in the curtain air bag module
(RH) (squib) harness

｠

Malfunction of the SRS-ECU

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 resistor

｠

MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.

ZC501967

AC404789

ZC5019680000

MB991824

MB991827

MB991910

Data link

connector

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before
connecting or disconnecting scan tool MB991958.

(1)

Connect scan tool MB991958. Refer to "How to connect the
scan tool P.52B-31."

(2)

Turn the ignition switch to the "ON" position.

(3)

Diagnose the CAN bus line.

(4)

Turn the ignition switch to the "LOCK" (OFF) position.

Q:Is the CAN bus line found to be normal?

YES:

Go to Step 2.

NO:

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

Diagnosis P.54D-17).

52B-116

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

SRS AIR BAG DIAGNOSIS

STEP 2. Recheck for diagnostic trouble code.

ZC501967

AC404789

ZC5019680000

MB991824

MB991827

MB991910

Data link

connector

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 Use Troubleshooting/Inspection Service Points -
How to Cope with Intermittent Malfunctions P.00-15).

STEP 3. Check by dummy resistor connection. (Using scan
tool MB991958, read the diagnostic trouble code.)

(1)

Disconnect the negative battery terminal.

(2)

Disconnect the D-08 intermediate connector (connection
between curtain air bag harness and floor harness).

ZC600211

D-08 Intermediate connector
(Curtain air bag harness side)

D-08
Intermediate
connector

(

Floor harness side

)

MB991865
(Dummy resistor: 3

)

MB991866

(Resistor harness)

0001

(3)

Connect special tool MB991865 to special tool MB991866.

Do not insert a probe into the terminal from its front side
directly, as the connector contact pressure may be
weakened.

(4)

Insert the probe of resistor harness, to which the dummy
resistor is installed, from the back of D-08 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 B1B20 set?

YES:

Go to Step 4.

NO:

Go to Step 5.

STEP 4. Resistance measurement at the C-27 SRS-ECU
connector

(1)

Disconnect the negative battery terminal.

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-117

SRS AIR BAG DIAGNOSIS

ZC600210

A

Lock lever

0000

(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-27
SRS-ECU connector.

(3)

Disconnect the D-08 intermediate connector (connection
between curtain air bag harness and floor harness).

ZC5007880027

C-27 Harness side
connector (front view)

(4)

Check for continuity between C-27 wiring harness side
connector terminal No. 39, 40 and body ground.
It should be open circuit.

Q:Is the check result normal?

YES:

Repair the wiring harness.

NO:

Go to Step 5.

STEP 5. Resistance measurement at the D-08 intermediate
connector.

(1)

Disconnect the negative battery terminal.

ZC602163

Locking
button

Flat-tipped screwdriver

Inflator

Curtain air bag wiring
harness side connector

0000

To prevent the air bag from deploying unintentionally,
disconnect the curtain air bag module connector D-104 to
short the squib circuit.

(2)

Disconnect curtain air bag module (RH) D-104. 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-08 intermediate connector (connection
between curtain air bag harness and floor harness).

ZC600212

D-08 Intermediate
connector (module side )
(front view)

A

A

4 mm or more

Terminal

Cable tie

Short
spring

Section
A - A

0001

(4)

Because the short spring is installed to the D-08 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.

52B-118

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

SRS AIR BAG DIAGNOSIS