Code No. C145F: Coupling Overload


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, always diagnose the CAN bus lines.

OPERATION



DIAGNOSIS CODE SET CONDITIONS




  • Drive mode-selector: 4WD or LOCK
  • When the load to the electronic control coupling is large, the mode is switched to the 2WD mode.

PROBABLE CAUSES


Current trouble
  • The driving conditions are severe.
  • Electronic control coupling failure (clutch slippage)
  • 4WD-ECU malfunction
  • Abnormality in ABS wheel speed signal
  • Abnormality in torque command value from the ABS/ASC-ECU
Past trouble
  • The past driving conditions were severe.
  • Electronic control coupling intermittent failure (clutch slippage)
  • Abnormality in ABS wheel speed signal
  • Abnormality in torque command value from the ABS/ASC-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 4.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting/CAN Bus Diagnostics Table ). On completion, go to Step 2.

STEP 2. Check whether the diagnosis code is reset after repairing the CAN bus line.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code No. C145F set?
Go to Step 3.
This diagnosis is complete.

STEP 3. M.U.T.-III data list
Check the following data list (Refer to ).

  • Item 07: CAN data (ABS/ASC)
  • Item 16: FL wheel speed sensor
  • Item 17: FR wheel speed sensor
  • Item 18: RL wheel speed sensor
  • Item 19: RR wheel speed sensor

Q. Is the check result normal?
Go to Step 4.
Troubleshoot the ABS system (Refer to GROUP 35B - Troubleshooting/Diagnosis Code Chart <Vehicles with ABS>), the ASC system (Refer to GROUP 35C - Troubleshooting/Diagnosis Code Chart <Vehicles with ASC>). Then go to Step 4.

STEP 4. M.U.T.-III actuator test
On a chassis dynamometer test, use M.U.T.-III to forcibly activate the electronic control coupling from 600 N·m to 730 N·m in 10 N·m steps.
Or on a test run of the vehicle, turn fully the steering wheel (lock condition) and use M.U.T.-III to forcibly activate the electronic control coupling at 500 N·m. Then drive the vehicle forward (or back) at about 10 km/h. If the system is normal, tight cornering phenomenon should occur.

  • Item 01: 4WD coupling control torque

Q. Does the electronic control coupling transfer the torque correctly?
Go to Step 5.
Replace the electronic control coupling. Then go to Step 6.

STEP 5. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code No. C145F set?
Replace 4WD-ECU (Refer to ). Then go to Step 6.
The code may be set because of some severe operational conditions such as a long-time high speed driving or long hill-climbing in 4WD condition.

STEP 6. Check whether the diagnosis code is reset.

Q. Is the diagnosis code No. C145F set?
Diagnose again from Step 1.
This diagnosis is complete.