Code No.C1621: 4WD Actuator Protection


caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis 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



DIAGNOSIS CODE SET CONDITION




  • The control is suspended to protect the electronic control coupling.

PROBABLE CAUSES



  • Electronic control coupling protection control status
  • Severe driving
  • Electronic control coupling failure (clutch slippage, etc.)
  • Outside temperature signal failure
  • Wheel speed signal failure
  • Engine-related failure (engine speed signal failure)
  • Ignition off time signal failure

DIAGNOSIS PROCEDURE

STEP 1. Check whether the diagnosis code is reset.
(1)To release the electronic control coupling (Centre) protection control, leave the vehicle for 15 minutes or longer after the high fluid temperature warning on the warning indicator disappears.
(2)Erase the diagnosis code.
(3)Carry out the test drive.
note Do not carry out the severe test drive.
(4)Check if the diagnosis code is set.

Q. Is diagnosis code No.C1621 set?
Go to Step 2.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 2. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-III to perform the CAN bus diagnosis.

Q. Is the check result normal?
Go to Step 4.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). After repairing the CAN bus line, go to Step 3.

STEP 3. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.C1621 set?
Go to Step 4.
This diagnosis is complete.

STEP 4. M.U.T.-III data list
Check the following data list (Refer to ).

  • Item No.12: Engine speed

Q. Is the check result normal?
Go to Step 5.
Perform the troubleshooting for the engine (Refer to GROUP 13A - Troubleshooting <4B1>, GROUP 13C -Troubleshooting <4J1>, GROUP 13D -Troubleshooting <4N1>).

STEP 5. M.U.T.-III data list
Check the following data list (Refer to ).

  • Item No.18: FL Wheel speed sensor
  • Item No.19: FR Wheel speed sensor
  • Item No.20: RL Wheel speed sensor
  • Item No.21: RR Wheel speed sensor

Q. Is the check result normal?
Go to Step 6.
Perform the ABS diagnosis code (Refer to GROUP 35B - Troubleshooting ) <Vehicles with ABS> or the ASC diagnosis code (Refer to GROUP 35C - Troubleshooting ) <Vehicles with ASC>.

STEP 6. M.U.T.-III data list
Check the following data list (Refer to ).

  • Item No.34: Ambient temperature (CAN input)

  • Item No.35: Ignition off time (CAN input)

Q. Is the check result normal?
Go to Step 7.
Perform the troubleshooting for the ETACS (Refer to GROUP 54A - ETACS, Troubleshooting ).

STEP 7. Check of the electronic control coupling
Refer to .

Q. Is the check result normal?
Go to Step 8.
Replace the electronic control coupling (Refer to ).

STEP 8. Check whether the diagnosis code is reset.
(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 diagnosis code.
(3)Carry out the test drive.
note Do not carry out the severe test drive.
(4)Check if the diagnosis code is set.

Q. Is diagnosis code No.C1621 set?
Replace the 4WD-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).