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

TSB Revision

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

TSB Revision

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)