C1622

DTC C1622: ACD Control System (Abnormal)

CAUTION:
^ If there is any problem in the CAN bus lines, an incorrect 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.

OPERATION
AWC-ECU provides power supply to the ACD proportioning valve.

DTC SET CONDITIONS
This diagnostic trouble code is set if any condition below is found:
^ When ACD clutch is protected.
^ When the current value of the ACD proportioning valve solenoid exceeds the specified value for a prolonged period.

PROBABLE CAUSES
^ The driving and road conditions are severe.
^ Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
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. After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.

Q: Is DTC No. C1622 set?
YES: Go to Step 3.
NO: This diagnosis is complete.

STEP 3. Scan tool diagnostic trouble code
Check other ACD diagnostic trouble code.

Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 4.

STEP 4. Check whether the DTC is reset.

Q: Is DTC No. C1622 set?
YES: Replace the AWC-ECU. Then go to Step 5.
NO: This diagnosis is complete. (The clutch protection activated in such driving or road condition as ACD control is applied for a prolonged period).

STEP 5. Check whether the DTC is reset.

Q: Is DTC No. C1622 set?
YES: Return to Step 1.
NO: This diagnosis is complete.