Mitsubishi Lancer Evolution X. Manual — part 188

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-217

DTC U0428: Communication error in steering wheel sensor

CAUTION

• If diagnostic trouble code U0428 is set in ASC-ECU,

always diagnose the CAN bus lines. If there is any fault
in the CAN bus lines, an incorrect DTC may be set.

• Whenever the ECU is replaced, ensure that the CAN

bus lines are normal.

• When the steering wheel sensor is replaced, always

perform calibration to make ASC-ECU learn the neutral
point. (Refer to

P.35C-289

.)

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

replaced, after turning the ignition switch ON and OFF
(vehicle information from ETACS-ECU is registered),
always perform the calibration of steering wheel sen-
sor, G and yaw rate sensor, brake fluid pressure sen-
sor, cut valve, and inlet valve.(Refer to

P.35C-287

,

P.35C-289

,

P.35C-294

, and

P.35C-295

.)

.

CIRCUIT OPERATION

The steering wheel sensor outputs the steering wheel status to
ASC-ECU via the CAN bus lines.

.

DTC SET CONDITIONS

This diagnostic trouble code is set when ASC-ECU has
detected the communication error in the steering wheel sensor.

.

PROBABLE CAUSES

• Steering wheel sensor malfunction
• ASC-ECU malfunction
• External noise interference

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-218

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 : Replace the steering wheel sensor.(Refer to

P.35C-305

.) Then 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 U0428 set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU).(Refer to

P.35C-298

.) Then go to Step 3.

NO : The procedure is complete.

STEP 3. Check whether the DTC is reset.
Q: Is DTC U0428 set?

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-219

DTC U0251: AWC time-out error (Local CAN)

DTC U0440: AWC communication error in AWC (Local CAN)

DTC U0435: AWC signal abnormality (Local CAN)

G AND YAW
RATE SENSOR

JOINT
CONNECTOR (7)

AWC-ECU

ASC-ECU

G and Yaw Rate Sensor Circuit

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-220

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

AWC-ECU outputs the signal to ASC-ECU via the special CAN
bus lines (Local CAN).

.

DTC SET CONDITIONS

These diagnostic trouble codes will be set under the cases
below.

DTC U0251

• Signals sent from AWC-ECU to ASC-ECU cannot be

received for a specified period.

DTC U0440

• Signals sent from AWC-ECU to ASC-ECU have an error.

DTC U0435

• A brake control request of outside the specified range is

output by AWC-ECU.

.

PROBABLE CAUSES

• Wiring harness or connector failure in special CAN bus lines

(Local CAN) between ASC-ECU and AWC-ECU

• AWC-ECU malfunction
• ASC-ECU malfunction

AC708948

Connector: A-05

A-05 (B)

AB

AC708950AN

C-46

C-50 (B)

Connectors: C-46, C-47, C-50

C-47