Mitsubishi Outlander XL. Manual - part 660

STEP 9. Resistance measurement at A-02 ASC-ECU
connector

ZC601293 0005

ASC-ECU

MB991997

Check harness

A-02 ASC-ECU 
harness connector

(1)

Disconnect  the  ASC-ECU  connector,  connect  special  tool
MB991997 to the harness-side connector, and then measure
the resistance at special tool connector side.

NOTE: 

Do not connect the special tool MB991997 to ASC-

ECU.

(2)

Resistance between the wheel speed sensor power supply
terminal (signal terminal) No. 36/the ground terminal No. 37
and the body ground

OK: No continuity

Q:Is the check result normal?

YES:

 Go to Step 11.

NO (Not normal at the terminal No. 36 or 37):

 Go to Step

10.

STEP 10. Connector check: A-02 ASC-ECU connector,
C-125 intermediate connector, D-114 wheel speed sensor
<RL> connector

Q:Is the check result normal?

YES:

 The short circuit in the wheel speed sensor <RL>

circuit may be present. Repair the wiring harness between
the A-02 ASC-ECU connector terminal No. 36/37 and the
D-114 wheel speed sensor <RL> connector terminal No. 1/2.

NO:

 Repair the defective connector.

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-47

DIAGNOSIS

STEP 11. Voltage measurement at the A-02 ASC-ECU
connector

ZC601292 0003

ASC-ECU

MB991997

Check harness

A-02 ASC-ECU 
harness connector

(1)

Disconnect  the  ASC-ECU  connector,  connect  special  tool
MB991997  to  the  ASC-ECU-side  connector  and  harness-
side connector, and then measure the voltage at the special
tool connector side.

(2)

Turn the ignition switch to the ON position.

(3)

Measure the voltage between the wheel speed sensor circuit
power supply terminal (signal terminal) No. 36 and the body
ground.

OK: Approximately battery voltage

Q:Is the check result normal?

YES:

 Go to Step 14.

NO:

 Go to Step 12.

STEP 12. Connector check: A-02 ASC-ECU connector,
C-125 intermediate connector, D-114 wheel speed sensor
<RL> connector

Q:Is the check result normal?

YES:

 Go to Step 13.

NO:

 Repair the defective connector.

STEP 13. Wiring harness check between A-02 ASC-ECU
connector terminal No. 36/37 and D-114 wheel speed sensor
<RL> connector terminal No. 1/2

｠

Check for open circuit in wheel speed sensor <RL> circuit

Q:Is the check result normal?

YES:

 Replace the wheel speed sensor.

NO:

 Repair the wiring harness.

STEP 14. Check whether the diagnostic trouble code is
reset.

(1)

Erase the diagnostic trouble code.

(2)

Drive the vehicle at 12mph (20 km/h) or more.

NOTE: 

The ABS warning light does not turn OFF in some

cases unless the vehicle runs at 12mph (20 km/h) or
higher.

Q:Is DTC C1027 set?

YES:

 Replace the ASC-ECU.

NO:

 Intermittent malfunction. (Refer to GROUP 00 - How

to Cope with Intermittent Malfunction P.00-15.)

35C-48

ACTIVE SKID CONTROL SYSTEM (ASC)

DIAGNOSIS

DTC C1032: Abnormality in RR wheel speed sensor signal

M13506100017USA0000010000

Wheel Speed Sensor Circuit

ASC-ECU

FRONT 
WHEEL 
SPEED 
SENSOR
(LH)

FRONT 
WHEEL 
SPEED 
SENSOR
(RH)

REAR 
WHEEL 
SPEED 
SENSOR
(LH)

REAR 
WHEEL 
SPEED 
SENSOR
(RH)

If there is any problem in the CAN bus lines, an incorrect
diagnostic trouble code may be set. Prior to this diagnosis,
diagnose the CAN bus lines. (Refer to GROUP 54D, Trouble
code diagnosis P.54D-17).

CIRCUIT 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
frequency 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

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-49

DIAGNOSIS

｠

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

｠

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

Past trouble

｠

When the diagnostic trouble code No. C102B is also set, carry
out diagnosis with particular emphasis on wiring harness 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 Cope with Intermittent
Malfunction P.00-15).

｠

When the diagnostic trouble code No. C102B is not set, the
following conditions may be present:

｠

Right or/and left wheels are rotated.

｠

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

｠

MB991997: ASC check harness

STEP 1. M.U.T.-III CAN bus diagnostics
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 54D - CAN

Bus Diagnostics table P.54D-17.) On completion, go to
Step 2.

35C-50

ACTIVE SKID CONTROL SYSTEM (ASC)

DIAGNOSIS