WOMS
P code powertrain Medium severity

P1199 Fuel Level Input Circuit Low

The OBD2 code P1199 indicates that the fuel level input circuit is reading a low voltage or signal, which may suggest a problem with the fuel level sensor or its wiring

Definition

The OBD2 code P1199 indicates that the fuel level input circuit is reading a low voltage or signal, which may suggest a problem with the fuel level sensor or its wiring

Common causes

  • Faulty fuel level sensor
  • Damaged wiring or connectors
  • Short circuit in the fuel level input circuit
  • Open circuit in the fuel level input circuit
  • Faulty engine control module (ECM)
  • Corroded connectors or terminals
  • Low fuel level or empty fuel tank

Common misdiagnoses

  • Faulty fuel level sensor
  • Wiring issues or shorts in the fuel level circuit
  • Fuel gauge malfunction
  • ECM/PCM issues
  • Fuel pump problems
  • Incorrect fuel level readings due to fuel contamination
  • Instrument cluster faults
  • Grounding issues in the electrical system

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues

  2. 2. Inspect the Fuel Level Sensor

  3. 3. Locate the fuel level sensor, which is usually found in the fuel tank

  4. 4. Check for any visible damage or corrosion on the sensor and its connectors

  5. 5. Ensure that the sensor is properly connected and that there are no loose or damaged wires

  6. 6. Test the Fuel Level Sensor

  7. 7. 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

  8. 8. If the resistance is outside the specified range, the sensor may be faulty and need replacement

  9. 9. Check the Wiring and Connectors

  10. 10. Inspect the wiring harness and connectors leading to the fuel level sensor for any signs of wear, fraying, or damage

  11. 11. Look for any signs of short circuits or open circuits in the wiring

  12. 12. Test the ECM

  13. 13. If the sensor and wiring appear to be in good condition, the issue may lie with the ECM itself

  14. 14. Check for any software updates or recalls related to the ECM that may address this issue

  15. 15. Check for Ground Issues

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

  17. 17. A poor ground connection can lead to incorrect voltage readings

  18. 18. Clear the Code and Test Drive

  19. 19. After performing any repairs or replacements, clear the trouble code using the OBD-II scanner

  20. 20. Take the vehicle for a test drive to see if the code reappears

  21. 21. Consult a Professional

  22. 22. If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P1199 code