DTC C1621: Electronic Control Coupling Solenoid Protection: Diagnosis

STEP 1. Check whether the DTC is set again.
1. To release the electronic control coupling protection control, leave the vehicle for 15 minutes or longer after the high fluid temperature warning on the warning indicator disappears.
2. Erase the DTC.
3. Carry out the test drive.
  NOTE: Do not carry out the severe test drive.
4. Check if the DTC is set.
Q: Is the DTC C1621 set?

YES: Go to Step 2.

NO: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
STEP 2. Scan tool (M.U.T.-IIISE) CAN bus diagnostics.
Use scan tool (M.U.T.-IIISE) to perform the CAN bus diagnosis. (Refer to CAN BUS DIAGNOSIS ).

Q: Is the check result normal?

YES: Go to Step 3.

NO: Repair the CAN bus lines (Refer to CAN BUS DIAGNOSTICS TABLE ).
STEP 3. Scan tool (M.U.T.-IIISE) data list
Check the following data list (Refer to SPECIAL FUNCTION ).
- Item No. 25: Engine speed
Q: Is the check result normal?

YES: Go to Step 4.

NO: Perform the troubleshooting for the engine (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
STEP 4. Scan tool (M.U.T.-IIISE) data list
Check the following data list (Refer to SPECIAL FUNCTION ).
- Item No. 35: Wheel speed (FL)
- Item No. 36: Wheel speed (FR)
- Item No. 37: Wheel speed (RL)
- Item No. 38: Wheel speed (RR)
Q: Is the check result normal?

YES: Go to Step 5.

NO: Perform the troubleshooting for the ASC (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
STEP 5. Scan tool (M.U.T.-IIISE) data list
Check the following data list (Refer to SPECIAL FUNCTION ).
- Item No. 51: Ambient temperature
- Item No. 52: Ignition off time
Q: Is the check result normal?

YES: Go to Step 6.

NO: Perform the troubleshooting for the ETACS (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
STEP 6. Check of the electronic control coupling
Refer to ELECTRONIC CONTROL COUPLING OPERATION CHECK <AWD> .

Q: Is the check result normal?

YES: Go to Step 7.

NO: Replace the electronic control coupling (Refer to S-AWC DRIVE MODE-SELECTOR <AWD> ).
STEP 7. Check whether the DTC is set again.
1. To release the electronic control coupling protection control, leave the vehicle for 15 minutes or longer after the high fluid temperature warning on the warning indicator disappears.
2. Erase the DTC.
3. Carry out the test drive.
  NOTE: Do not carry out the severe test drive.
4. Check if the DTC is set.
Q: Is the DTC C1621 set?

YES: Replace the AWC-ECU (Refer to AWC-ECU <AWD> ).

NO: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).