WOMS
B code body Medium severity

B1220 Fuel Tank Pressure Sensor Circuit Open

The OBD2 code B1220 indicates that there is an open circuit in the fuel tank pressure sensor, which means the sensor is not receiving power or is not properly connected, leading to a failure in monitoring fuel tank...

Definition

The OBD2 code B1220 indicates that there is an open circuit in the fuel tank pressure sensor, which means the sensor is not receiving power or is not properly connected, leading to a failure in monitoring fuel tank pressure

Common causes

  • Faulty fuel tank pressure sensor
  • Open or damaged wiring in the sensor circuit
  • Poor electrical connections or corroded connectors
  • Faulty engine control module (ECM)
  • Blown fuse related to the sensor circuit
  • Grounding issues in the circuit

Common misdiagnoses

  • Faulty fuel tank pressure sensor
  • Wiring issues or shorts in the circuit
  • Faulty engine control module (ECM)
  • Evaporative emissions system leaks
  • Faulty fuel cap or seal
  • Issues with the purge valve or vent valve
  • Vacuum leaks in the intake system
  • Incorrectly diagnosed fuel system problems

Troubleshooting steps

  1. 1. Check the Code and Freeze Frame Data

    Use an OBD-II scanner to confirm the B1220 code is present

  2. 2. Review freeze frame data to understand the conditions under which the code was set

  3. 3. Visual Inspection

    Inspect the wiring and connectors related to the fuel tank pressure sensor. Look for

  4. 4. Damaged, frayed, or corroded wires

  5. 5. Loose or disconnected connectors

  6. 6. Signs of moisture or dirt in the connectors

  7. 7. Test the Fuel Tank Pressure Sensor

    Locate the fuel tank pressure sensor and check its resistance using a multimeter. Compare the readings to the specifications in the vehicle’s service manual

  8. 8. If the sensor is out of specification, it may need to be replaced

  9. 9. Check the Power and Ground

    Verify that the fuel tank pressure sensor is receiving the correct voltage (usually 5V or 12V, depending on the vehicle)

  10. 10. Check the ground connection for the sensor to ensure it is solid and free of corrosion

  11. 11. Inspect the Fuel Tank and Evaporative Emission System

    Check for any physical damage to the fuel tank or the evaporative emission system components

  12. 12. Look for leaks in the system, as this can affect the pressure readings

  13. 13. Test the Circuit

    Use a multimeter to check for continuity in the wiring between the sensor and the engine control module (ECM)

  14. 14. Look for any open circuits or shorts that could be causing the issue

  15. 15. Check for Other Codes

    Look for any additional trouble codes that may provide more context or indicate related issues

  16. 16. Clear the Codes and Test Drive

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

  17. 17. Take the vehicle for a test drive to see if the code returns

  18. 18. Consult the Service Manual

    If the issue persists, consult the vehicle’s service manual for specific diagnostic procedures related to the fuel tank pressure sensor and circuit

  19. 19. Seek Professional Help

    If you are unable to resolve the issue after following these steps, consider seeking assistance from a professional mechanic or automotive technician. By following these troubleshooting steps, you should be able to identify the cause of the B1220 code and take appropriate action to resolve it