WOMS
U code network Medium severity

U2977 Lost Communication with the Steering Angle Sensor

The OBD2 code U2977 indicates a loss of communication with the steering angle sensor, which may affect the vehicle's stability control and steering systems

Definition

The OBD2 code U2977 indicates a loss of communication with the steering angle sensor, which may affect the vehicle's stability control and steering systems

Common causes

  • Faulty steering angle sensor
  • Damaged wiring or connectors
  • Poor electrical connections
  • Malfunctioning vehicle control module
  • Software issues or updates needed
  • Corrosion or dirt in connectors
  • Power supply issues to the sensor
  • Faulty CAN bus communication

Common misdiagnoses

  • Faulty steering angle sensor
  • Wiring issues or damaged connectors
  • Faulty ABS module
  • Faulty power steering control module
  • Incorrectly calibrated steering angle sensor
  • Software or firmware issues in the vehicle's control modules
  • Battery or power supply issues affecting sensor operation

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Sometimes, related codes can provide more context for the issue

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors associated with the steering angle sensor for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or damaged

  4. 4. Test the Steering Angle Sensor

    Sensor Functionality: If possible, test the steering angle sensor using a multimeter or an oscilloscope to ensure it is functioning correctly

  5. 5. Calibration

    Some vehicles require the steering angle sensor to be calibrated after installation or repair. Check the vehicle’s service manual for calibration procedures

  6. 6. Check Power and Ground

    Power Supply: Verify that the steering angle sensor is receiving the correct voltage. Use a multimeter to check the power supply at the sensor connector

  7. 7. Ground Connection

    Ensure that the ground connection for the sensor is intact and providing a good ground

  8. 8. Inspect the CAN Bus

    Communication Lines: Since the steering angle sensor communicates over the CAN bus, check for any issues with the CAN wiring. Look for shorts, opens, or interference

  9. 9. CAN Bus Termination

    Ensure that the CAN bus is properly terminated at both ends

  10. 10. Check for Software Issues

    ECU Updates: Sometimes, the issue can be resolved by updating the vehicle’s ECU software. Check with the manufacturer for any available updates

  11. 11. Resetting the System

    Clear the trouble codes and see if the code returns after a test drive. This can sometimes reset communication issues

  12. 12. Inspect Related Components

    Steering Column: Check for any issues with the steering column or related components that may affect the sensor’s operation

  13. 13. Other Sensors

    Inspect other sensors that may be related to the steering system, such as the yaw rate sensor or ABS sensors

  14. 14. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the steering angle sensor or communication issues for your specific vehicle make and model. Manufacturers often release TSBs for known issues

  15. 15. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized diagnostic tools and experience with your specific vehicle.Conclusion By following these troubleshooting steps, you can systematically identify and resolve the issue related to the U2977 code. Always refer to the vehicle’s service manual for specific procedures and specifications related to your vehicle model