WOMS
U code network Medium severity

U1651 Invalid or Missing Data for Vehicle Speed

The OBD2 code U1651 indicates that the vehicle's control module has detected invalid or missing data related to vehicle speed, which may affect the performance of various systems

Definition

The OBD2 code U1651 indicates that the vehicle's control module has detected invalid or missing data related to vehicle speed, which may affect the performance of various systems

Common causes

  • Faulty vehicle speed sensor
  • Damaged wiring or connectors
  • Poor ground connection
  • Malfunctioning engine control module (ECM)
  • Issues with the transmission control module (TCM)
  • Faulty ABS module
  • Corrupted data communication between modules
  • Software glitches or updates needed in the vehicle's control modules

Common misdiagnoses

  • Faulty Vehicle Speed Sensor (VSS)
  • Malfunctioning Engine Control Module (ECM)
  • Wiring issues or shorts in the speed sensor circuit
  • Faulty ABS module
  • Incorrect tire size or calibration issues
  • Problems with the transmission control module (TCM)
  • Issues with the instrument cluster
  • Faulty or corroded connectors and terminals

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Codes related to the transmission, speed sensor, or other modules can provide additional context

  2. 2. Inspect Vehicle Speed Sensor (VSS)

    Locate the vehicle speed sensor and inspect it for any physical damage or disconnection

  3. 3. Check the wiring and connectors for corrosion, fraying, or loose connections

  4. 4. Test the VSS with a multimeter to ensure it is functioning correctly. Refer to the vehicle's service manual for specific resistance values

  5. 5. Examine Wiring and Connectors

    Inspect the wiring harnesses and connectors associated with the VSS and the modules that communicate vehicle speed data

  6. 6. Look for any signs of wear, damage, or poor connections that could affect data transmission

  7. 7. Check the CAN Bus

    Use a scan tool to monitor the CAN bus for any communication issues. Ensure that all modules are communicating properly

  8. 8. Check for any short circuits or open circuits in the CAN wiring

  9. 9. Inspect the Instrument Cluster

    If the vehicle speed data is not being displayed correctly on the instrument cluster, there may be an issue with the cluster itself

  10. 10. Check for any faults in the cluster that could prevent it from receiving or displaying speed data

  11. 11. Test the PCM/ECM

    The Powertrain Control Module (PCM) or Engine Control Module (ECM) may be at fault. Check for software updates or reprogramming needs

  12. 12. If other modules are not receiving data from the PCM, it may need to be tested or replaced

  13. 13. Clear Codes and Test Drive

    After performing inspections and repairs, clear the trouble codes using the OBD-II scanner

  14. 14. Take the vehicle for a test drive to see if the code reappears. Monitor the vehicle speed data during the drive

  15. 15. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the U1651 code or vehicle speed sensor issues for your specific make and model. Manufacturers may have known fixes or updates

  16. 16. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose complex communication issues. By following these troubleshooting steps, you should be able to identify and resolve the underlying issue causing the U1651 code