Mitsubishi Lancer Evolution X. Manual — part 173

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-157

STEP 6. Check of steering wheel sensor installation status
Check that the steering wheel sensor is installed correctly.
Q: Is the check result normal?

YES : Go to Step 7.
NO : Install the steering wheel sensor correctly. (Refer to

P.35C-305

.) Then go to Step 7.

STEP 7. Wheel alignment check
Refer to GROUP 33 − On-vehicles service

P.33-8

.

Q: Is the check result normal?

YES : After checking the wheel alignment, perform the

calibration of steering wheel sensor to make
ASC-ECU relearn the neutral point. (Refer to

P.35C-289

.) Then go to Step 8.

NO : After adjusting the wheel alignment, perform the

calibration of steering wheel sensor to make
ASC-ECU relearn the neutral point. (Refer to

P.35C-289

.) Then go to Step 8.

STEP 8. Scan tool service data
Check the following service data. (Refer to

P.35C-276

.)

• Item 11: Steering angle

Q: Is the check result normal?

YES : Go to Step 9.
NO : Replace the steering wheel sensor. (Refer to

P.35C-305

.) Then go to Step 10.

STEP 9. Check whether the DTC is reset.
Drive the vehicle for 15 seconds or more at 25 mph (40 km/h)
or higher.
Q: Is DTC C123B set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU). (Refer to

P.35C-298

.) Then go to Step

10.

NO : Intermittent malfunction. (Refer to GROUP 00 − How

to Cope with Intermittent Malfunction

P.00-15

.)

STEP 10. Check whether the DTC is reset.
Drive the vehicle for 15 seconds or more at 25 mph (40 km/h)
or higher.
Q: Is DTC C123B set?

YES : Return to Step 1.
NO : The procedure is complete.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-158

DTC C2200: Abnormality in ASC-ECU

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.

• Whenever the ECU is replaced, ensure that the CAN

bus lines are normal.

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

replaced, always perform the calibration of steering
wheel sensor, G and yaw rate sensor, brake fluid pres-
sure sensor, cut valve, and inlet valve.(Refer to

P.35C-287

,

P.35C-289

,

P.35C-294

, and

P.35C-295

.)

.

CIRCUIT OPERATION

ASC-ECU controls ASC by calculating the data sent from the
wheel speed sensor, steering wheel sensor, and G and yaw
rate sensor.

.

DTC SET CONDITIONS

This diagnostic trouble code is set when ASC-ECU has mal-
function.

.

PROBABLE CAUSES

ASC-ECU malfunction

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

YES : Go to Step 2.
NO : Repair the CAN bus lines. (Refer to GROUP 54C −

Troubleshooting

P.54C-15

.) After repairing the CAN

bus line, go to Step 3.

STEP 2. Check whether the DTC is reset.
Q: Is DTC C2200 set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU).(Refer to

P.35C-298

.) Then go to Step 3.

NO : Intermittent malfunction. (Refer to GROUP 00 − How

to Cope with Intermittent Malfunction

P.00-15

.)

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-159

STEP 3. Check whether the DTC is reset.
Q: Is DTC C2200 set?

YES : Return to Step 1.
NO : This diagnosis is complete.

DTC C2101: Abnormality in battery voltage (high voltage)

Solenoid Valve,Motor and ASC-ECU Power Supply Circuit

FUSIBLE
LINK

27

FUSIBLE
LINK

26

ETACS-
ECU

ASC-ECU

FUSIBLE
LINK

34

JOINT
CONNECTOR
(3)

POWER
SUPPLY

MOTOR
POWER
SUPPLY

SOLENOID
VALVE POWER
SUPPLY

AC804606

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-160

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.

• Whenever the ECU is replaced, ensure that the CAN

bus lines are normal.

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

replaced, always perform the calibration of steering
wheel sensor, G and yaw rate sensor, brake fluid pres-
sure sensor, cut valve, and inlet valve.(Refer to

P.35C-287

,

P.35C-289

,

P.35C-294

, and

P.35C-295

.)

.

CIRCUIT OPERATION

• ASC-ECU contains the power supply circuit (terminal No.

32) for the solenoid valve. The solenoid valve is energized
by the valve relay, which is incorporated in ASC-ECU.

• ASC-ECU contains the power supply circuit (terminal No. 2)

for ASC-ECU, and the power is supplied from the fusible
link No. 34 through the multi-purpose fuse No. 17.

• The valve relay in ASC-ECU is energized at all times, and

the solenoid valve is always energized while the system is
in operation unless the initial check is in progress when the
ignition switch is turned ON, or unless the periodical system
check is in progress.

.

DTC SET CONDITIONS

This diagnostic trouble code is set when the ASC-ECU power
supply voltage and solenoid valve power supply voltage
become 18.0 ± 1.0 V or higher.

.

AC708948

Connector: A-05

A-05 (B)

AB

AC708950

Connectors: C-103, 130

AJ

C-103 (B)

C-130 (BR)

AC708972AM

Connectors: C-309, C-315

C-309 (B)

C-315

ETACS-ECU