WOMS
C code chassis Medium severity

C0238 Wheel Speed Mismatch

The OBD2 code C0238 indicates a wheel speed mismatch, which means that the wheel speed sensors are detecting inconsistent speeds between the wheels, potentially affecting the vehicle's traction control or anti-lock...

Definition

The OBD2 code C0238 indicates a wheel speed mismatch, which means that the wheel speed sensors are detecting inconsistent speeds between the wheels, potentially affecting the vehicle's traction control or anti-lock braking system

Common causes

  • Faulty wheel speed sensor
  • Damaged wiring or connectors
  • Incorrectly installed or misaligned wheel speed sensor
  • ABS module malfunction
  • Brake system issues
  • Tire size discrepancies
  • Wheel bearing problems
  • Calibration issues after tire or wheel changes

Common misdiagnoses

  • ABS Module Failure
  • Wheel Speed Sensor Failure
  • Brake System Issues
  • Tire Size Mismatch
  • Differential Problems
  • Wiring or Connector Issues
  • Control Module Software Issues
  • Brake Rotor or Drum Issues
  • Hub Assembly Problems
  • Alignment Issues

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are other issues present

  2. 2. Inspect Wheel Speed Sensors

  3. 3. Visually inspect the wheel speed sensors for any signs of damage, dirt, or debris

  4. 4. Ensure that the sensors are properly connected and that the wiring is intact

  5. 5. Check Sensor Alignment

    Ensure that the wheel speed sensors are correctly aligned and positioned. Misalignment can lead to incorrect readings

  6. 6. Test Wheel Speed Sensors

  7. 7. Use a multimeter or an oscilloscope to test the output of the wheel speed sensors. Compare the readings from each sensor while the vehicle is in motion

  8. 8. Look for discrepancies in the readings between the left and right wheels or between the front and rear wheels

  9. 9. Inspect the Tone Rings

  10. 10. Check the tone rings (or reluctor rings) for any damage, cracks, or debris. These rings are essential for the proper functioning of the wheel speed sensors

  11. 11. Ensure that the tone rings are clean and free from rust or corrosion

  12. 12. Check for Mechanical Issues

  13. 13. Inspect the wheel bearings and suspension components for wear or damage. Mechanical issues can affect wheel speed readings

  14. 14. Ensure that the tires are properly inflated and that they are of the same size and type

  15. 15. Examine the ABS Module

  16. 16. If all sensors and mechanical components are functioning correctly, the issue may lie within the ABS control module. Check for any signs of damage or corrosion

  17. 17. If necessary, perform a software update or reset the ABS module

  18. 18. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code reappears

  19. 19. Consult a Professional

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with ABS systems and can perform more advanced diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the cause of the C0238 code