Mitsubishi Lancer Evolution X. Manual - part 179

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-181

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 2.

STEP 2. Check for diagnostic trouble codes of other
systems
Check if diagnostic trouble code No. U0125 is also set in
ASC-ECU.
Q: Is DTC U0125 set?

YES : Perform troubleshooting for the diagnostic trouble

code that is set. (Refer to

P.35C-212

.) Then go to

Step 3.

NO : Go to Step 3.

STEP 3. Check whether the DTC is reset.
Q: Is DTC C123C set?

YES : Go to Step 4.
NO : The procedure is complete.

STEP 4. Check of wheel speed sensor-related diagnostic
trouble code
Using scan tool MB991958, check if the wheel speed sen-
sor-related or steering wheel sensor-related diagnostic trouble
code is set. (Refer to

P.35C-22

Q: Is any DTC set?

YES : Perform troubleshooting for the diagnostic trouble

code that is set. (Refer to

P.35C-22

NO : Go to Step 5.

STEP 5. Check of G and yaw rate sensor installation status
Check that the G and yaw rate sensor is installed correctly.
Q: Is the check result normal?

YES : After checking the G and yaw rate sensor, perform

the calibration of the G and yaw rate sensor to make
ASC-ECU relearn the neutral point.(Refer to

P.35C-287

.) Then go to Step 6.

NO : Reinstall the G and yaw rate sensor correctly. (Refer

P.35C-304

.) Then go to Step 10.

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-182

STEP 6. Scan tool service data
Check the following service data. (Refer to

P.35C-276

• Item 08: Lateral G-sensor
• Item 12: Yaw rate sensor

Q: Is the check result normal?

YES : Go to Step 7.
NO : Replace the G and yaw rate sensor. (Refer to

P.35C-304

.) Then go to Step 10.

STEP 7. 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 8.
NO : Install the steering wheel sensor correctly. (Refer to

P.35C-305

.) Then go to Step 8.

STEP 8. Wheel alignment check
Refer to

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 9.

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 9.

STEP 9. Scan tool service data
Check the following service data. (Refer to

P.35C-276

• Item 11: Steering angle sensor

Q: Is the check result normal?

YES : Go to Step 10.
NO : Replace the steering wheel sensor. (Refer to

P.35C-305

.) Then go to Step 10.

STEP 10. Check whether the DTC is reset.
Q: Is DTC C123C set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU).(Refer to

P.35C-298

.) Then go to Step 11.

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

to Cope with Intermittent Malfunction

P.00-15

STEP 11. Check whether the DTC is reset.
Q: Is DTC C123C set?

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-183

DTC C2204: Internal abnormality in G and yaw rate 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.

• Do not drop the G and yaw rate sensor or subject it to a

shock.

• When the G and yaw rate sensor is replaced, always

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

P.35C-287

• 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

• ASC-ECU supplies power to the G and yaw rate sensor at

the terminal No. 1.

• The G and yaw rate sensor outputs the signal to ASC-ECU

via the local CAN bus lines.

DTC SET CONDITIONS

This diagnostic trouble code is set if any malfunction below is
found:

• Abnormality is detected by the self-diagnosis of the G and

yaw rate sensor.

• Output value of the G and yaw rate sensor is not within the

standard value range.

NOTE: This diagnostic trouble code may be set when G and
yaw rate sensor is put on the turntable turning at high speed.

PROBABLE CAUSES

• Improper installation of the G and yaw rate sensor
• Damaged wiring harness and connectors
• G and yaw rate sensor malfunction
• 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

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-184

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 2.

STEP 2. Check for diagnostic trouble codes of other
systems
Check if diagnostic trouble code No. U0125 is also set in
ASC-ECU.
Q: Is DTC U0125 set?

YES : Perform troubleshooting for the diagnostic trouble

code that is set. (Refer to

P.35C-212

.) Then go to

Step 3.

NO : Go to Step 3.

STEP 3. Check whether the DTC is reset.
Q: Is DTC C2204 set?

YES : Go to Step 4.
NO : The procedure is complete.

STEP 4. Scan tool service data
Check the following service data. (Refer to

P.35C-276

• Item 08: Lateral G sensor
• Item 09: G sensor
• Item 12: Yaw rate sensor
• Item 73: Lateral G sensor offset
• Item 97: Yaw rate sensor offset

Q: Is the check result normal?