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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 set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the steering wheel sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point (Refer to ).
 
 
OPERATION
ASC-ECU monitors if the output of G and yaw rate sensor is normal or not.
 
 
 
DTC SET CONDITIONS
This DTC is set if any malfunction below is found:
  • The output value of lateral G and yaw rate is abnormal.
  • When abnormality is detected by comparing the value output from the lateral G and yaw rate with the one from the steering wheel sensor and wheel speed sensor
 
 
 
PROBABLE CAUSES
  • Steering wheel sensor malfunction
  • Improperly installed steering wheel sensor
  • Malfunction of wheel speed sensor
  • ASC-ECU malfunction
  • External noise interference
 
 
 
 
DIAGNOSIS
STEP 1. Check the other sensor-related DTC.
Use scan tool (M.U.T.-IIISE) to check whether the wheel speed sensor-related or steering wheel sensor-related DTC is set or not.
Is the DTC set?
Troubleshoot for the relevant DTC (Refer to ).
Go to Step 2.
 
STEP 2. Check whether the ASC-ECU is installed properly.
Check whether the ASC-ECU is installed correctly. (Refer to ).
Is the check result normal?
Go to Step 3.
Repair it.
 
STEP 3. Using scan tool (M.U.T.-IIISE), check data list.
Check the following data list (Refer to ).
  • Item 06: Yaw rate sensor
  • Item 08: Lateral G sensor
Is the check result normal?
Go to Step 4.
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
 
STEP 4. Check for column switch assembly (integrated with steering wheel sensor).
Refer to GROUP 54A - Column Switch .
Is the check result normal?
Go to Step 5.
Repair it.
 
STEP 5. Front wheel alignment check.
Refer to GROUP 33 -On-vehicle Service/Front wheel alignment check .
Is the check result normal?
Go to Step 6.
Repair it.
 
STEP 6. Using scan tool (M.U.T.-IIISE), check data list.
Check the following data list (Refer to ).
  • Item 05: Steering angle sensor
Is the check result normal?
Go to Step 7.
Replace the column switch assembly (integrated with steering wheel sensor) (Refer to GROUP 54A - Column Switch ).
 
STEP 7. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Turn the ignition switch to the "ON" position.
(4) Turn the steering wheel to either right or left at 20 km/h (12 mph) or higher.
noteThe ASC warning/operation light and the ASC OFF light may remain on until the vehicle speed reaches approx. 10 km/h (6 mph), then the steering wheel is turned to either right or left.
Is DTC C123C set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).