WOMS
U code network Medium severity

U1087 Lost Communication with Fuel Level Sensor 'A'

The OBD2 code U1087 indicates that there is a loss of communication with the fuel level sensor 'A', which may affect the vehicle's ability to accurately read the fuel level

Definition

The OBD2 code U1087 indicates that there is a loss of communication with the fuel level sensor 'A', which may affect the vehicle's ability to accurately read the fuel level

Common causes

  • Faulty fuel level sensor
  • Damaged wiring or connectors
  • Poor ground connection
  • Failed fuel pump module
  • Malfunctioning engine control module (ECM)
  • Corroded or loose electrical connections
  • Short circuit in the wiring harness
  • Intermittent signal loss due to vibration or movement

Common misdiagnoses

  • Faulty fuel level sensor
  • Wiring issues or damaged connectors
  • Faulty engine control module (ECM)
  • Faulty instrument cluster
  • Grounding issues
  • Faulty fuel pump module
  • Corrupted software or firmware in the ECM
  • Issues with the fuel gauge itself

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 the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors associated with the fuel level 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 pushed back

  4. 4. Test the Fuel Level Sensor

    Resistance Check: Use a multimeter to measure the resistance of the fuel level sensor. Compare the readings to the specifications provided in the vehicle’s service manual

  5. 5. Functionality Test

    If possible, test the sensor by applying a known voltage and checking if the output changes accordingly

  6. 6. Check the Fuel Level Sensor Circuit

    Continuity Test: Perform a continuity test on the wiring between the fuel level sensor and the engine control module (ECM) to ensure there are no breaks in the circuit

  7. 7. Voltage Test

    Check for proper voltage supply to the fuel level sensor. Ensure that the sensor is receiving the correct voltage as specified in the service manual

  8. 8. Inspect the ECM

    Connections: Check the connections at the ECM for any signs of damage or corrosion

  9. 9. Software Updates

    Ensure that the ECM has the latest software updates, as sometimes communication issues can be resolved with a software update

  10. 10. Check for Ground Issues

    Ensure that the ground connections for the fuel level sensor and the ECM are secure and free of corrosion

  11. 11. Scan for Communication Issues

    Use a scan tool to check for communication between the ECM and the fuel level sensor. If the sensor is not communicating, it may need to be replaced

  12. 12. Replace the Fuel Level Sensor

    If all tests indicate that the sensor is faulty, consider replacing the fuel level sensor

  13. 13. Clear Codes and Test Drive

    After performing repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  14. 14. Consult a Professional

    If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis.Additional Tips: - Always refer to the vehicle’s service manual for specific testing procedures and specifications. - Be cautious when working with electrical components to avoid causing further damage. By following these troubleshooting steps, you should be able to identify the cause of the U1087 code and take appropriate action to resolve the issue