Code No.C123C: G and Yaw Rate Sensor System (Faulty Signal)


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 initialise the steering angle correction amount stored in AWC-ECU. (Item No.1: Steering angle correction amount initialisation ).
  • Do not drop the G and yaw rate sensor or subject it to a shock.
  • When G and yaw rate sensor is replaced, calibrate G and yaw rate sensor (refer to GROUP 35C - On-vehicle Service )

OPERATION



DIAGNOSIS CODE SET CONDITIONS




  • Abnormality in G and yaw rate sensor output value
  • This diagnosis code is set when AWC-ECU determines that an abnormality is present by comparing the measurement values of G and yaw rate sensor with the calculation value of G and yaw rate calculated by the measurement values of the wheel speed sensor and steering wheel sensor.

PROBABLE CAUSES



  • Improper installation of G and yaw rate sensor
  • Malfunction of G and yaw rate sensor
  • Malfunction of wheel speed sensor
  • Malfunction of steering wheel sensor
  • Malfunction of ASC-ECU
  • Malfunction of AWC-ECU

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 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 G and yaw rate sensor installation status.
Check that the G and yaw rate sensor is installed correctly. (Refer to GROUP 35C - G and Yaw Rate Sensor ).

Q. Is the check result normal?
Go to Step 6.
Reinstall the 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.26: Yaw rate sensor
  • Item No.29: Lateral G sensor

Q. Is the check result normal?
Go to Step 7.
Replace the G and yaw rate sensor. (Refer to GROUP 35C - 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 initialise AWC-ECU steering angle correction amount (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 initialise AWC-ECU steering angle correction amount (Refer to ). Then go to Step 9.

STEP 9. M.U.T.-III data list.
Item 11: Steering wheel sensor (refer to ).

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 AWC-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.