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C1143 Wheel Speed Sensor LR Tone Ring Tooth Missing Fault

The OBD2 code C1143 indicates that there is a fault related to the left rear (LR) wheel speed sensor, specifically that a tooth is missing from the tone ring, which can affect the sensor's ability to accurately read...

Definition

The OBD2 code C1143 indicates that there is a fault related to the left rear (LR) wheel speed sensor, specifically that a tooth is missing from the tone ring, which can affect the sensor's ability to accurately read wheel speed

Common causes

  • Damaged or missing tone ring
  • Corroded or damaged wheel speed sensor
  • Misalignment of the wheel speed sensor
  • Debris or dirt on the tone ring or sensor
  • Faulty wiring or connectors
  • Brake system issues
  • Wheel bearing problems

Common misdiagnoses

  • Faulty wheel speed sensor
  • Damaged wiring or connectors
  • ABS control module failure
  • Brake system issues
  • Incorrect tire size or pressure
  • Wheel bearing problems
  • Misalignment or suspension issues
  • Faulty tone ring or reluctor wheel

Troubleshooting steps

  1. 1. Visual Inspection

    Check the Tone Ring: Inspect the left rear wheel speed sensor tone ring for any visible damage, such as missing teeth or cracks

  2. 2. Sensor Condition

    Examine the wheel speed sensor itself for any signs of damage, corrosion, or dirt buildup

  3. 3. Wiring and Connectors

    Inspect the wiring harness and connectors leading to the wheel speed sensor for any signs of fraying, corrosion, or disconnection

  4. 4. Sensor Testing

    Resistance Check: Use a multimeter to check the resistance of the wheel speed sensor. Compare the readings to the manufacturer's specifications

  5. 5. Signal Testing

    If possible, use an oscilloscope to check the output signal from the wheel speed sensor while the wheel is being rotated. The signal should show a consistent pattern

  6. 6. Check for Other Codes

    Scan for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide more context to the issue

  7. 7. Inspect Wheel Assembly

    Brake Components: Check the brake components for any interference that might affect the tone ring or sensor

  8. 8. Wheel Bearing

    Inspect the wheel bearing for wear or damage, as this can affect the alignment of the tone ring and sensor

  9. 9. Clear Codes and Test Drive

    Clear the Code: After performing any repairs or adjustments, clear the trouble codes using an OBD-II scanner

  10. 10. Test Drive

    Take the vehicle for a test drive to see if the code reappears. Monitor the ABS and traction control systems to ensure they are functioning correctly

  11. 11. Replace Components if Necessary

    Replace Tone Ring: If the tone ring is damaged or has missing teeth, it will need to be replaced

  12. 12. Replace Wheel Speed Sensor

    If the sensor is faulty or damaged, replace it with a new one

  13. 13. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or technician who has experience with ABS and traction control systems.Additional Tips: - Always refer to the vehicle's service manual for specific diagnostic procedures and specifications. - Ensure that any replacement parts are compatible with the vehicle's make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the C1143 code