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DTC C123C: G and Yaw Rate Sensor System (Lateral G and Yaw Rate Sensor Output Signal)
 
 
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.
  • 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 set in the AWC-ECU (Item No. 1: Steering angle 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 set when the abnormality below is detected:
  • Abnormality in G and yaw rate sensor output value
  • The yaw rate correction amount of the G and yaw rate sensor exceeds the specified range.
  • This DTC 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
  • Hydraulic unit (incorporating G and Yaw rate sensor) improperly installed
  • 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

 
 
DIAGNOSIS
STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics.
Use scan tool (M.U.T.-IIISE) to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Diagnosis, Can Bus Diagnostics Table ).
 
STEP 2. Scan tool (M.U.T.-IIISE) DTC.
Check the ASC DTC (Refer to GROUP 35C - Diagnosis, Diagnosis, Diagnostic Trouble Code Chart ).
Is the check result normal?
Perform the relevant troubleshooting.
Go to Step 3.
 
STEP 3. Scan tool (M.U.T.-IIISE) other system DTC.
Check if the wheel speed sensor-related, or steering wheel sensor-related DTC is set.
Is the DTC set?
Perform the relevant troubleshooting.
Go to Step 4.
 
STEP 4. 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 5.
Reinstall the hydraulic unit (integrated with G and yaw rate sensor) correctly, and then carry out the calibration of the G and yaw rate sensor to make ASC-ECU learn the neutral point. Then go to Step 5.
 
STEP 5. Scan tool (M.U.T.-IIISE) data list.
Check the following data list (Refer to ).
  • Item No.39: Yaw rate
  • Item No.40: Lateral G
Is the check result normal?
Go to Step 6.
Replace the hydraulic unit (integrated with G and yaw rate sensor), and then carry out the calibration of the G and yaw rate sensor to make ASC-ECU learn the neutral point.
 
STEP 6. 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 7.
Install the steering wheel sensor correctly. Then go to Step 7.
 
STEP 7. 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 set in the AWC-ECU (Refer to ). Then go to Step 8.
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 set in the AWC-ECU (Refer to ). Then go to Step 8.
 
STEP 8. Scan tool (M.U.T.-IIISE) data list.
Check the following data list (Refer to ).
  • Item No.21: Steering angle
Is the check result normal?
Go to Step 9.
Replace the steering wheel sensor (Refer to GROUP 35C - Steering Wheel Sensor ).
 
STEP 9. Check whether the DTC is set again.
Is the DTC C123C set?
Replace the AWC-ECU (Refer to ).
This diagnosis is complete.