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DTC C123C: Sensor Cluster Malfunction
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC may be stored. 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 AWC-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
AWC-ECU receives the G and yaw rate sensor data from ASC-ECU via the CAN communication.
 
 
DTC SET CONDITIONS
This DTC is stored when the abnormality below is detected:
  • Abnormality in G and yaw rate sensor output value
  • Abnormality is detected by a comparison of output value from the G and yaw rate sensor with the output values from wheel speed sensor and steering wheel sensor.
 
 
PROBABLE CAUSES
  • Malfunction of G and yaw rate sensor
  • Malfunction of wheel speed sensor
  • Improper installation of steering wheel sensor
  • Malfunction of steering wheel sensor
  • Malfunction of AWC-ECU

 
 
DIAGNOSTIC PROCEDURE
STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics.
Use scan tool (M.U.T.-III) to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Diagnosis, Can Bus Diagnostics Table ). After repairing the CAN bus line, go to Step 2 .
 
STEP 2. Check whether the DTC is stored again.
Is DTC No.C123C stored?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Scan tool (M.U.T.-III) DTC.
Check the ASC DTC. (Refer to GROUP 35C - Diagnosis, Diagnostic Trouble Code Chart ).
Is the check result normal?
Perform the relevant troubleshooting.
Go to Step 4.
 
STEP 4. Scan tool (M.U.T.-III) other system DTC.
Check if the wheel speed sensor-related, or steering wheel sensor-related DTC is stored.
Is the DTC stored?
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) ).
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. Scan tool (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
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 ).
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.
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 AWC-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 AWC-ECU(Refer to ). Then go to Step 9.
 
STEP 9. Scan tool (M.U.T.-III) data list.
Check the following data list (Refer to ).
  • Item No.8: Steering angle sensor
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 DTC is stored again.
Is DTC No.C123C stored?
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 DTC is stored again.
Is DTC No.C123C stored?
Return to Step 1.
This diagnosis is complete.