Mitsubishi Outlander GS45X. Manual — part 402

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-35

STEP 5. Resistance measurement at A-02 ASC-ECU
connector
(1) Disconnect the ASC-ECU connector, connect special tool

ASC check harness (MB991997) to the harness-side
connector, and then measure the resistance at the special
tool connector side.
NOTE: Do not connect the special tool to ASC-ECU.

(2) Measure the resistance between the wheel speed sensor

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

OK: No continuity

Q: Is the check result normal?

YES : Go to Step 8.
NO (Not normal at the terminal No.36 or 37) : Go to Step

6.

STEP 6. Connector check: A-02 ASC-ECU connector,
C-129 intermediate connector, D-114 rear wheel speed
sensor <LH> connector
Q: Is the check result normal?

YES : Go to Step 7.
NO : Repair the defective connector.

STEP 7. Wiring harness check between A-02 ASC-ECU
connector terminal No.36 and D-114 rear wheel speed
sensor <LH> connector terminal No.1 and between A-02
ASC-ECU connector terminal No.37 and D-114 rear wheel
speed sensor <LH> connector terminal No.2

• Check for short circuit in rear wheel speed sensor <LH> cir-

cuit

Q: Is the check result normal?

YES : Replace the wheel speed sensor <RL> (Refer to

P.35C-288

).

NO : Repair the wiring harness.

AC611137 BY

ASC-ECU

MB991997

Check harness

A-02 ASC-ECU
harness connector

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-36

STEP 8. Voltage measurement at the A-02 ASC-ECU
connector
(1) Disconnect the ASC-ECU connector, connect special tool

ASC check harness (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

power supply terminal (signal terminal) No.36 and body
ground, and between the ground terminal No.37 and body
ground.

OK:

Terminal No.36 and body ground: Approximately

system voltage

Terminal No.37 and body ground: 1 volt or less

Q: Is the check result normal?

YES : Go to Step 9.
NO : Go to Step 11.

STEP 9. Wiring harness check between A-02 ASC-ECU
connector terminal No.36 and D-114 rear wheel speed
sensor <LH> connector terminal No.1 and between A-02
ASC-ECU connector terminal No.37 and D-114 rear wheel
speed sensor <LH> connector terminal No.2.

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

Q: Is the check result normal?

YES : Go to Step 10.
NO : Repair the wiring harness.

STEP 10. Check for wheel speed sensor <RL> as a single
unit
Refer to

P.35C-289

.

Q: Is the check result normal?

YES : Go to Step 11.
NO : Replace the wheel speed sensor <RL> (Refer to

P.35C-288

).

STEP 11. Connector check: A-02 ASC-ECU connector,
D-114 rear wheel speed sensor <LH> connector
Q: Is the check result normal?

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

AC611138AM

ASC-ECU

MB991997

A-02 ASC-ECU
harness connector

Check harness

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-37

STEP 12. Check whether the diagnostic trouble code is
reset.
(1) Erase the diagnostic trouble code.
(2) Drive the vehicle at 12 mph (20 km/h) or higher.

NOTE: The ABS warning light does not turn OFF in some
cases unless the vehicle runs at 12 mph (20 km/h) or
higher.

Q: Is DTC C1020 set?

YES : Replace the hydraulic unit (integrated with ASC-ECU)

(Refer to

P.35C-287

).

NO : Intermittent malfunction (Refer to GROUP 00

− How

to Use Troubleshooting/How to Cope with Intermittent
Malfunctions

P.00-15

).

DTC C102B Abnormality in RR wheel speed sensor circuit

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)

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-38

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 voltage fluctuation in each wheel speed
sensor circuit. If ASC-ECU detects the open or short circuit in
the circuit, it will set a diagnostic trouble code.

.

AC901112

Connector: A-02

A-02 (B)

AF

AC901075BC

Connector: C-129

AC901080AN

Connector: D-133

D-133 (B)