Code No.C123C: Sensor Cluster Malfunction <ASC>


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.
  • When the steering wheel sensor is replaced, calibrate the steering wheel sensor (Refer to GROUP 35C - On-vehicle Service ), and reset the steering wheel sensor correction amount stored in the 4WD-ECU. (Item No. 1: SAS adjusted value ).
  • When hydraulic unit (integrated with G and yaw rate sensor) is replaced, calibrate G and yaw rate sensor (Refer to GROUP 35C - On-vehicle Service .)

OPERATION


4WD-ECU receives the G and yaw rate sensor data from ASC-ECU via the CAN communication.

DIAGNOSIS CODE SET CONDITIONS


This diagnosis code is set when the abnormality below is detected:

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. 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 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.C123C set?
Go to Step 3.
This diagnosis is complete.

STEP 3. M.U.T.-III diagnosis code.
Check the ASC diagnosis code. (Refer to GROUP 35C - Troubleshooting ).

Q. Is the check result normal?
Perform the relevant troubleshooting.
Go to Step 4.

STEP 4. M.U.T.-III other system diagnosis code.
Check if the wheel speed sensor-related, or steering wheel sensor-related diagnosis code is set.

Q. Is the diagnosis code set?
Perform the relevant troubleshooting.
Go to Step 5.

STEP 5. Check of hydraulic unit (integrated with G and yaw rate sensor) installation status.
Check that the hydraulic unit (integrated with G and yaw rate sensor) is installed correctly (Refer to GROUP 35C - Hydraulic unit (integrated with G and yaw rate sensor) ).

Q. Is the check result normal?
Go to Step 6.
Reinstall the hydraulic unit (integrated with G and yaw rate sensor) correctly. Then go to Step 6.

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

  • Item No.22: Yaw rate sensor
  • Item No.23: Lateral G sensor

Q. Is the check result normal?
Go to Step 7.
Replace the hydraulic unit (integrated with G and yaw rate sensor) is installed correctly (Refer to GROUP 35C - Hydraulic unit (integrated with G and yaw rate sensor) ). Then go to Step 11.

STEP 7. Check of steering wheel sensor installation status.
Check that the steering wheel sensor is installed correctly (Refer to GROUP 35C - Steering Wheel Sensor ).

Q. Is the check result normal?
Go to Step 8.
Install the steering wheel sensor correctly. Then go to Step 8.

STEP 8. Wheel alignment check.

Q. Is the check result normal?
After checking the wheel alignment, calibrate the steering wheel sensor (Refer to GROUP 35C - On-vehicle Service ), and reset the steering wheel sensor correction amount stored in the 4WD-ECU(Refer to ). Then go to Step 9.
After adjusting the wheel alignment, calibrate the steering wheel sensor (Refer to GROUP 35C - On-vehicle Service ), and reset the steering wheel sensor correction amount stored in the 4WD-ECU(Refer to ). Then go to Step 9.

STEP 9. M.U.T.-III data list.
Check the following data list (Refer to).

  • Item No.8: Steering angle sensor

Q. Is the check result normal?
Go to Step 10.
Replace the steering wheel sensor (Refer to GROUP 35C - Steering Wheel Sensor ). Then go to Step 10.

STEP 10. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.C123C set?
Replace the 4WD-ECU (Refer to ). Then go to Step 11.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 11. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.C123C set?
Return to Step 1.
This diagnosis is complete.