Mitsubishi Outlander GS45X. Manual - part 401

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-31

STEP 9. Wiring harness check between A-02 ASC-ECU 
connector terminal No.34 and A-59 front wheel speed 
sensor <RH> connector terminal No.1 and between A-02 
ASC-ECU connector terminal No.33 and A-59 front wheel 
speed sensor <RH> connector terminal No.2.

• Check for open circuit in front wheel speed sensor <RH> 

circuit.

Q: Is the check result normal?

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

STEP 10. Check for wheel speed sensor <FR> 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 <FR> (Refer to 

P.35C-288

).

STEP 11. Connector check: A-02 ASC-ECU connector, A-59 
front wheel speed sensor <RH> connector
Q: Is the check result normal?

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

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 C1015 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

).

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-32

DTC C1020 Abnormality in RL 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)

AC901112

Connector: A-02

A-02 (B)

AF

AC901075BC

Connector: C-129

AC709496

AM

Connector: D-114

D-114 (B)

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-33

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.

.

PROBABLE CAUSES

Current trouble

• Damaged wiring harness and connectors

• Noise interference

• Malfunction of wheel speed sensor

• ASC-ECU malfunction

Past trouble

• 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 (GROUP 00 

− How to Use Trou-

bleshooting/How to Treat Past Trouble 

P.00-17

).

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-34

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-10

). On 

completion, go to Step 2.

STEP 2. DTC recheck after resetting CAN bus lines
Q: Is DTC C1020 set?

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

STEP 3. Using scan tool MB991958, check the data list
Check the following data list (Refer to 

P.35C-270

).

• Item No.03: RL wheel speed sensor

Q: Is the check result normal?

YES : Intermittent malfunction (Refer to GROUP 00 

− How 

to Use Troubleshooting/How to Cope with Intermittent 
Malfunctions 

P.00-15

).

NO :  Go to Step 4.

STEP 4. Voltage measurement at the 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 voltage at the special tool 
connector side.
NOTE: Do not connect the special tool to ASC-ECU.

(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 the body 
ground and between the wheel speed sensor ground 
terminal No.37 and the body ground.

OK: 1 Volt or less

Q: Is the check result normal?

YES : Go to Step 5.
NO (Not normal at the terminal No.36 or 37) : Go to Step 

6.

AC611137

ASC-ECU

MB991997

A-02 ASC-ECU 
harness connector

BH

Check harness