B1220 – Fuel Tank Pressure Sensor Circuit Open

The ODBII 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.

The severity of ODBII code B1220 is moderate.

Common Causes For: B1219 Fuel Tank Pressure Sensor Circuit Failure

• 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 misdiagnosis for B1220 Fuel Tank Pressure Sensor Circuit Open

• 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

Common Troubleshooting Steps

When dealing with an OBD-II code B1220, which indicates a “Fuel Tank Pressure Sensor Circuit Open,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check the Code and Freeze Frame Data: Use an OBD-II scanner to confirm the B1220 code is present.
• Review freeze frame data to understand the conditions under which the code was set.
• Visual Inspection: Inspect the wiring and connectors related to the fuel tank pressure sensor. Look for:
• Damaged, frayed, or corroded wires.
• Loose or disconnected connectors.
• Signs of moisture or dirt in the connectors.
• 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.
• If the sensor is out of specification, it may need to be replaced.
• 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).
• Check the ground connection for the sensor to ensure it is solid and free of corrosion.
• Inspect the Fuel Tank and Evaporative Emission System: Check for any physical damage to the fuel tank or the evaporative emission system components.
• Look for leaks in the system, as this can affect the pressure readings.
• Test the Circuit: Use a multimeter to check for continuity in the wiring between the sensor and the engine control module (ECM).
• Look for any open circuits or shorts that could be causing the issue.
• Check for Other Codes: Look for any additional trouble codes that may provide more context or indicate related issues.
• Clear the Codes and Test Drive: After performing the checks and repairs, clear the codes using the OBD-II scanner.
• Take the vehicle for a test drive to see if the code returns.
• 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.
• 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.