Mitsubishi Evolution X. Manual — part 782

DIAGNOSIS

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ACTIVE SKID CONTROL SYSTEM (ASC)

35C-135

STEP 9. Check whether the DTC is reset.
Q: Is DTC C121E set?

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

DTC C2000: Abnormality in wheel fluid pressure sensor circuit

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

The wheel cylinder pressure sensor is integrated into the
hydraulic unit. It converts the signal of brake fluid pressure in
wheel cylinder of each wheel to the voltage value, then outputs
the value to ASC-ECU.

DTC SET CONDITIONS

This diagnostic trouble code is set when the voltage value,
which was converted from the signal of brake fluid pressure in
wheel cylinder of each wheel and sent by the wheel cylinder
pressure sensor to ASC-ECU, is outside the standard range.

PROBABLE CAUSES

• Damaged wiring harness and connectors

• Malfunction of hydraulic unit (with built-in wheel cylinder

pressure sensor)

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

• MB991997: ASC check harness

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-136

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: Is DTC C2000 set?

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

STEP 3. Check whether the DTC is reset.
Q: Is DTC C2000 set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU).(Refer to

P.35C-272

.) Then go to Step 4.

NO : Intermittent malfunction. (Refer to GROUP 00

− How

to Cope with Intermittent Malfunction

P.00-15

STEP 4. Check whether the DTC is reset.
Q: Is DTC C2000 set?

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

DTC C2001: Abnormality in wheel fluid pressure sensor output signal

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

• The wheel cylinder pressure sensor is integrated into the

hydraulic unit. It converts the signal of brake fluid pressure
in wheel cylinder of each wheel to the voltage value, then
outputs the value to ASC-ECU.

• The wheel cylinder pressure sensor contains the following

two signal output sections: Fluid pressure signal output sec-
tion and fluid pressure and temperature signal output sec-
tion.

DIAGNOSIS

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ACTIVE SKID CONTROL SYSTEM (ASC)

35C-137

DTC SET CONDITIONS

This diagnostic trouble codes will be set under the cases
below:

• The pressure sensor offset is outside the specified range.

(Pressure is generated at all times)

• The estimated pressure sensor temperature is not normal.

PROBABLE CAUSES

• Damaged wiring harness and connectors

• Incorrect adjustment of brake pedal height

• Master cylinder malfunction

• Brake booster malfunction

• Incorrect installation position of stoplight switch

• Malfunction of the stoplight switch

• Brake drag

• Malfunction of the ASC-ECU

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

• MB991997: ASC check harness

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: Is DTC C2001 set?

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

STEP 3. Check for diagnostic trouble codes of other
systems
Check if the diagnostic trouble code No. C121E is set in
ASC-ECU.
Q: Is the check result normal?

YES : Go to Step 4.
NO : Carry out the diagnosis for the diagnostic trouble code

No. C121E. (Refer to

P.35C-132

DIAGNOSIS

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ACTIVE SKID CONTROL SYSTEM (ASC)

35C-138

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

P.35C-255

• Item 129: FL wheel cylinder pressure

• Item 130: FR wheel cylinder pressure

• Item 131: RL wheel cylinder pressure