Mitsubishi Outlander GS45X. Manual — part 408

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-59

CAUTION

• If there is any problem in the CAN bus lines, an incor-

rect diagnostic trouble code may be set. Prior to this
diagnosis, diagnose the CAN bus lines (Refer to
GROUP 54C

− CAN Bus Line Diagnostic Flow

P.54C-10

).

• Whenever ECU is replaced, ensure that the CAN bus

lines are normal.

• When the hydraulic unit (integrated with ASC-ECU) is

replaced, always carry out the calibration of the steer-
ing wheel sensor, the G and yaw rate sensor and brake
fluid pressure sensor (Refer to

P.35C-283

,

P.35C-282

and

P.35C-284

).

.

OPERATION

• The wheel speed sensor is a kind of a pulse generator. It

consists of encoders (a plate on which north and south pole
sides of the magnets are arranged alternately) for detecting
the wheel speed which rotates at the same speed of the
wheels and wheel speed sensors. This sensor outputs fre-
quency pulse signals in proportion to the wheel speed.

• The pulse signals, which the wheel speed sensor creates,

are sent to ASC-ECU. ASC-ECU uses the frequency of the
pulse signals to determine the wheel speed.

.

DTC SET CONDITIONS

ASC-ECU monitors the signals from each wheel speed sensor
while the vehicle is being driven. If any fault below is found in
these sensor signals, ASC-ECU will set the relevant diagnostic
trouble code.

• Irregular change in the wheel speed sensor signal

• Wheel speed sensor signal continuously indicates high

value.

.

PROBABLE CAUSES

Current trouble

• Excessive gap between the wheel speed sensor and the

wheel speed detection encoder

• Adhesion of foreign materials on the wheel speed sensor

AC901080AN

Connector: D-133

D-133 (B)

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-60

• Adhesion of foreign materials on the wheel speed detection

encoder

• Wheel bearing malfunction

• Malfunction of wheel speed sensor

• Damaged wiring harness and connectors

• External noise interference

• Improper installation of the wheel speed sensor

• Deformation of the wheel speed detection encoder

• ASC-ECU malfunction

• Disturbance of magnetization pattern for wheel speed

detection encoder

• The number of poles on the Magnetic encoder for wheel

speed detection (N-pole and S-pole) is changed

Past trouble

• When the diagnostic trouble code No. C102B is also set,

carry out diagnosis with particular emphasis on wiring har-
ness and connector failures between ASC-ECU and the
wheel speed sensor. For diagnosis procedures, refer to
How to treat past trouble (Refer to GROUP 00

− How to

Use Troubleshooting/How to Treat Past Trouble

P.00-17

).

• When the diagnostic trouble code No. C102B is not set, the

following conditions may be present:

• Some wheels slip

• Unstable vehicle attitude

• External noise interference

• Vehicle ran with the parking brake applied.

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

STEP 1. Using scan tool MB991958, diagnose the CAN bus
lines.
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 3.
NO : Repair the CAN bus lines (Refer to GROUP 54C

−

CAN Bus Diagnostics Table

P.54C-17

). On

completion, go to Step 2.

STEP 2. DTC recheck after resetting CAN bus lines
Q: Is DTC C1032 set?

YES : Go to Step 3.
NO : The procedure is complete.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-61

STEP 3. Using scan tool MB991958, check the DTC
Check that the DTC C102B is also set.
Q: Is DTC C102B also set?

YES : Perform the diagnosis for the DTC C102B (Refer to

P.35C-37

).

NO : Go to Step 4.

STEP 4. Connector check: A-02 ASC-ECU connector,
C-129 intermediate connector, D-133 rear wheel speed
sensor <RH> connector
Q: Is the check result normal?

YES : Go to Step 5.
NO : Repair the defective connector. Then go to Step 12.

STEP 5. Wiring harness check between A-03 ASC-ECU
connector terminal No.43 and D-133 rear wheel speed
sensor <RH> connector terminal No.1, and between A-03
ASC-ECU connector terminal No.42 and D-133 rear wheel
speed sensor <RH> connector terminal No.2.
Q: Is the check result normal?

YES : Go to Step 6.
NO : Repair the wiring harness. Then go to Step 12.

STEP 6. Check for wheel speed sensor <RR> installation
Check how the wheel speed sensor <RR> is installed (Discon-
nection of wheel speed sensor <RR>, loose mounting bolt,
etc.).
Q: Is the check result normal?

YES : Go to Step 7.
NO : Reinstall the wheel speed sensor <RR> correctly

(Refer to

P.35C-288

). Then go to Step 7.

STEP 7. Check for wheel speed sensor <RR> output
current
Refer to

P.35C-277

.

Q: Is the check result normal?

YES : Go to Step 8.
NO : Replace the wheel speed sensor <RR> (Refer to

P.35C-288

). Then go to Step 11.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-62

STEP 8. Check for wheel bearing looseness
NOTE:

.

•

Loose wheel bearing may increase the gap between the
wheel speed sensor <RR> and the wheel speed detection
magnet encoder.

•

Check the Rear wheel hub assembly <RR (FWD)> (Refer to
GROUP 27A

−

Wheel Bearing Play Check

P.27A-6

).

•

Check the wheel bearing <RR (AWD)> for looseness (Refer
to GROUP 27B

−

Wheel Bearing Play Check

P.27B-17

).

Q: Is the check result normal?

YES : Go to Step 9.
NO (FWD) : Replace the rear wheel hub assembly <RR>

(Refer to GROUP 27A

− Rear axle hub assembly

P.27A-8

). Then go to Step 12.

NO (AWD) : Replace the wheel bearing <RR> (Refer to

GROUP 27B

− Rear axle hub assembly

P.27B-19

).

Then go to Step 12.

STEP 9. Check of wheel speed detection encoder
Check the encoder for adhesion of foreign materials or defor-
mation.
Q: Is the check result normal?

YES : Go to Step 10.
NO (Adhesion of foreign materials) : Remove the foreign

materials and clean the encoder so as not to disturb
the magnetization pattern on it while taking care of the
magnet, magnetic substance, and magnetic
attraction. Then go to Step 12.

NO <Deformation (FWD)> : Replace the rear wheel hub

assembly <RR> (Refer to GROUP 27A

− Rear axle

hub assembly

P.27A-8

). Then go to Step 12.

NO <Deformation (AWD)> : Replace the wheel bearing

<RR> (Refer to GROUP 27B

− Rear axle hub

assembly

P.27B-19

). Then go to Step 12.

AC704785

Rear hub

Oil seal

Ball bearing

Magnetic
encoder

AB

Magnetic
encoder

Rear hub
assembly

Rear wheel bearing

<FWD>

<AWD>