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Mitsubishi Evolution X. Manual - part 800

DIAGNOSIS

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ACTIVE SKID CONTROL SYSTEM (ASC)

35C-207

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

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-279

.) Then go to Step 2.

NO : Repair the CAN bus lines. (Refer to GROUP 54C

−

Troubleshooting

P.54C-14

.) 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-272

.) 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 SKID CONTROL SYSTEM (ASC)

35C-208

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

DTC U0440: AWC communication error (Local CAN)

DTC U0435: AWC signal abnormality (Local CAN)

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

CIRCUIT OPERATION

S-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 S-AWC-ECU to ASC-ECU cannot be

received for a specified period.

DTC U0440

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

DTC U0435

• A brake control request of outside the specified range is

output by S-AWC-ECU.

PROBABLE CAUSES

• Wiring harness or connector failure in special CAN bus lines

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

• S-AWC-ECU malfunction

• ASC-ECU malfunction

AC708948

Connector: A-05

A-05 (B)

AC708950AN

C-46

C-50 (B)

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

C-47

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-209

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 3.
NO : Repair the CAN bus lines. (Refer to GROUP 54C

−

Troubleshooting

P.54C-14

.) After repairing the CAN

bus line, go to Step 2.

STEP 2. DTC recheck after repairing the CAN bus line
Q: Are DTC U0251, U0440, and U0435 set?

YES : Go to Step 3.
NO : This diagnosis is complete.

STEP 3. Diagnostic trouble code check of other systems
using scan tool MB991958
Using scan tool MB991958, check if a diagnostic trouble code
is set in S-AWC-ECU.
Q: Is other DTC set?

YES : Troubleshoot the relevant diagnostic trouble code,

and then go to Step 8.

NO : Go to Step 4.

STEP 4. Connector check: A-05 ASC-ECU connector, C-46
S-AWC-ECU connector, C-47 intermediate connector, C-50
joint connector
Q: Is the check result normal?

YES : Go to Step 5.
NO : Repair the connector, and then go to Step 8.

STEP 5. Wiring harness check between A-05 ASC-ECU
connector terminal No. 18 and C-46 S-AWC-ECU connector
terminal No. 9, between A-05 ASC-ECU connector terminal
No. 19 and C-46 S-AWC-ECU connector terminal No. 10

• Open or short circuit check of communication circuit

Q: Is the check result normal?

YES : Go to Step 6.
NO : Repair the wiring harness, and then go to Step 8.