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C code chassis High severity

C1237 Speed Wheel Rear Input Signal Missing

The OBD2 code C1237 indicates that the vehicle's rear speed wheel input signal is missing, which typically suggests a problem with the wheel speed sensor or its circuit in the rear wheels

Definition

The OBD2 code C1237 indicates that the vehicle's rear speed wheel input signal is missing, which typically suggests a problem with the wheel speed sensor or its circuit in the rear wheels

Common causes

  • Faulty wheel speed sensor
  • Damaged wiring or connectors
  • Poor electrical connections
  • Malfunctioning ABS module
  • Issues with the vehicle's control module
  • Brake system problems
  • Wheel bearing issues
  • Corrosion or dirt on sensor or connector

Common misdiagnoses

  • Faulty wheel speed sensor
  • Damaged wiring or connectors
  • ABS control module failure
  • Incorrect tire size or type
  • Faulty brake system components
  • Issues with the vehicle's computer or software
  • Problems with the rear differential or axle assembly

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. Locate the rear wheel speed sensors and inspect them for any physical damage, corrosion, or loose connections

  4. 4. Ensure that the wiring harness and connectors are secure and free from dirt or moisture

  5. 5. Test Wheel Speed Sensors

  6. 6. Use a multimeter to test the resistance of the wheel speed sensors. Compare the readings to the manufacturer's specifications

  7. 7. If the sensor is not functioning correctly, it may need to be replaced

  8. 8. Check for Wiring Issues

  9. 9. Inspect the wiring and connectors leading to the wheel speed sensors for any signs of wear, fraying, or damage

  10. 10. Look for any broken or shorted wires that could be causing a loss of signal

  11. 11. Examine the ABS Module

  12. 12. Check the ABS control module for any signs of damage or corrosion

  13. 13. Ensure that the module is receiving power and ground as specified in the service manual

  14. 14. Scan for ABS System Issues

  15. 15. Use a specialized ABS scanner to check for any faults within the ABS system that may not be captured by a standard OBD-II scanner

  16. 16. Look for any stored codes that may indicate a problem with the ABS module or other related components

  17. 17. Inspect Brake Components

  18. 18. Check the brake components, including the brake pads and rotors, to ensure they are in good condition and not interfering with the wheel speed sensors

  19. 19. Make sure that the sensors are properly aligned and positioned

  20. 20. Clear Codes and Test Drive

  21. 21. After performing the necessary repairs or adjustments, clear the trouble codes using the OBD-II scanner

  22. 22. 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 properly

  23. 23. Refer to the vehicle's service manual for specific diagnostic procedures and specifications related to the C1237 code and the ABS system

  24. 24. Seek Professional Help

  25. 25. 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 issue related to the C1237 code