Mitsubishi Evolution X. Manual - part 790

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-167

DTC C1210: Abnormality in G and yaw rate sensor (longitudinal G 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-267

.)

• 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-266

.)

• 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-266

, 

P.35C-267

, 

P.35C-268

, and 

P.35C-269

.)

.

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 special CAN bus lines.

.

DTC SET CONDITIONS

This diagnostic trouble code is set if any malfunction below is 
detected.

• Longitudinal G value output from G and yaw rate sensor is 

abnormal.

• Abnormality is detected by the self-diagnosis of the longitu-

dinal G sensor.

.

PROBABLE CAUSES

• G and yaw rate sensor malfunction

• ASC-ECU malfunction

• External noise interference

• The G and yaw rate sensor for FWD is installed.

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 SKID CONTROL SYSTEM (ASC)

35C-168

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. Check whether the DTC is reset.
Q: Is DTC C1210 set?

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

STEP 3. Scan tool service data
Check the following service data. (Refer to 

P.35C-255

.)

• Item 09: G sensor

Q: Is the check result normal?

YES : Go to Step 4.
NO :  Go to Step 5.

STEP 4. Check of G and yaw rate sensor part number
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-266

.) Then go to Step 5.

NO :  Replace the G and yaw rate sensor. (Refer to 

P.35C-278

.) Then go to Step 6.

STEP 5. Check whether the DTC is reset.
Q: Is DTC C1210 set?

YES : Replace the G and yaw rate sensor. (Refer to 

P.35C-278

.) Then go to Step 6.

NO :  The procedure is complete.

STEP 6. Check whether the DTC is reset.
Q: Is DTC C1210 set?

YES : Replace the hydraulic unit (incorporates in 

ASC-ECU).(Refer to 

P.35C-272

.) Then go to Step 7.

NO :  Intermittent malfunction. (Refer to GROUP 00 

− How 

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 7. Check whether the DTC is reset.
Q: Is DTC C1210 set?

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

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-169

DTC C1242: Abnormality in G and yaw rate sensor (longitudinal G 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-266

.)

• 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-266

, 

P.35C-267

, 

P.35C-268

, and 

P.35C-269

.)

.

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 special CAN bus lines.

.

DTC SET CONDITIONS

This diagnostic trouble code is set when an abnormality is 
detected by a comparison of the longitudinal G value output 
from G and yaw rate sensor with the wheel speed value output 
from wheel speed sensor.

.

PROBABLE CAUSES

• Improper installation of the G and yaw rate sensor

• G and yaw rate sensor malfunction

• Wheel speed sensor malfunction

• ASC-ECU malfunction

• External noise interference

NOTE: This DTC may be set also when the vehicle is driven on 
the four-wheel drum tester.

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 SKID CONTROL SYSTEM (ASC)

35C-170

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-14

.) 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-202

.) Then go to 

Step 3.

NO :  Go to Step 3.

STEP 3. Check whether the DTC is reset.
Q: Is DTC C1242 set?

YES : Go to Step 4.
NO :  This diagnosis 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 diagnostic trouble code is set. (Refer to 

P.35C-20

.)

Q: Is any DTC set?

YES : Perform troubleshooting for the diagnostic trouble 

code that is set. (Refer to 

P.35C-20

.)

NO :  Go to Step 5.

STEP 5. G and yaw rate sensor check
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-266

.) Then go to Step 6.

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

to 

P.35C-278

.) Then go to Step 8.

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

P.35C-255

.)

• Item 09: G sensor

Q: Is the check result normal?

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

P.35C-278

.) Then go to Step 7.