Mitsubishi Lancer Evolution X. Manual — part 183

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-197

STEP 2. DTC recheck after repairing the CAN bus line
Q: Is DTC C121A set?

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

STEP 3. Steering wheel sensor calibration
Perform calibration of the steering wheel sensor. ( Refer to

P.35C-289

.)

Q: Has the calibration succeeded?

YES : Go to Step 4.
NO : Replace the steering wheel sensor.(Refer to

P.35C-305

.) Then go to Step 4.

STEP 4. Check whether the DTC is reset.
Q: Is DTC C121A set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU).(Refer to

P.35C-298

.) Then go to Step 5.

NO : The procedure is complete.

STEP 5. Check whether the DTC is reset.
Q: Is DTC C121A set?

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

DTC C2205: Internal malfunction of steering wheel sensor

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 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

Steering wheel sensor sends its status signal to ASC-ECU.

.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-198

DTC SET CONDITIONS

This diagnostic trouble code is set when ASC-ECU detects that
the steering wheel sensor has a malfunction.

.

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 : 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 4.

STEP 2. Check whether the DTC is reset.
Q: Is DTC C2205 set?

YES : Replace the steering wheel sensor.(Refer to

P.35C-305

.) Then go to Step 3.

NO : The procedure is complete.

STEP 3. Check whether the DTC is reset.
Q: Is DTC C2205 set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU).(Refer to

P.35C-298

.) Then go to Step 4.

NO : The procedure is complete.

STEP 4. Check whether the DTC is reset.
Q: Is DTC C2205 set?

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-199

DTC C1608: Implausible diagnosis data

ASC-ECU Power Supply Circuit

FUSIBLE
LINK

27

SOLENOID
VALVE
POWER
SUPPLY

ETACS-
ECU

ASC-ECU

POWER
SUPPLY

FUSIBLE
LINK

34

JOINT
CONNECTOR (3)

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-200

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, 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

.)

• When the ASC-ECU connector or battery terminal is

disconnected with the ignition switch ON, this diagnos-
tic trouble code may be set.

• When this diagnostic trouble code is set, no other fail-

ure information will be set.

.

CIRCUIT OPERATION

• The ASC-ECU stores diagnostic trouble codes and failure

information in the EEPROM

*

.

• ASC-ECU (EEPROM

*

) contains the power supply circuit

(terminal No.2).

NOTE:

*

:EEPROM (Electrical Erasable and Programmable

ROM)

.

AC708948

Connector: A-05

A-05 (B)

AB

AC708950

Connectors: C-103, 130

AJ

C-103 (B)

C-130 (BR)

AC708972AS

Connectors: C-309, C-315, C-317

ETACS-ECU

C-315

C-317

C-309 (B)