B1222 – Fuel Temperature Sensor #1 Circuit Failure

The ODBII code B1222 indicates a malfunction in the fuel temperature sensor #1 circuit, which may involve issues such as an open circuit, short circuit, or a faulty sensor affecting fuel temperature readings.

The severity of ODBII code B1222 is generally considered moderate.

Common Causes For: B1220 Fuel Tank Pressure Sensor Circuit Open

• Faulty fuel temperature sensor
• Damaged wiring or connectors
• Short circuit in the sensor circuit
• Open circuit in the sensor circuit
• Poor ground connection
• Corrosion at the sensor or connector
• Faulty engine control module (ECM)

Common misdiagnosis for B1222 Fuel Temperature Sensor #1 Circuit Failure

• Faulty fuel temperature sensor
• Wiring issues or shorts in the sensor circuit
• Faulty engine control module (ECM)
• Incorrect fuel type or contamination
• Issues with the fuel pump
• Problems with the fuel gauge or fuel level sensor
• Faulty connectors or terminals in the circuit
• Other sensor failures (e.g., coolant temperature sensor)

Common Troubleshooting Steps

When dealing with an OBD-II code B1222, which indicates a “Fuel Temperature Sensor #1 Circuit Failure,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect the Fuel Temperature Sensor: Locate the fuel temperature sensor and visually inspect it for any signs of damage, corrosion, or loose connections.
• Ensure that the sensor is properly connected to the wiring harness.
• Test the Sensor: Use a multimeter to test the resistance of the fuel temperature sensor. Compare the readings to the specifications provided in the vehicle’s service manual.
• If the resistance is outside the specified range, the sensor may be faulty and should be replaced.
• Check Wiring and Connectors: Inspect the wiring harness and connectors leading to the fuel temperature sensor for any signs of wear, fraying, or damage.
• Look for any signs of short circuits or open circuits in the wiring.
• Check for Ground Issues: Ensure that the fuel temperature sensor has a good ground connection. A poor ground can lead to incorrect readings and trigger the code.
• Inspect the Fuel System: Check the fuel system for any issues that could affect the temperature readings, such as fuel contamination or improper fuel levels.
• Clear the Codes: After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner.
• Take the vehicle for a test drive to see if the code reappears.
• Monitor Live Data: Use the OBD-II scanner to monitor live data from the fuel temperature sensor while the engine is running. This can help you determine if the sensor is functioning correctly.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the fuel temperature sensor for your specific vehicle make and model. Manufacturers may have issued guidance on common issues and fixes.
• Seek Professional Help: If you are unable to resolve the issue after following these steps, it may be best to consult a professional mechanic or technician who has experience with your vehicle. By following these troubleshooting steps, you should be able to identify the cause of the B1222 code and take appropriate action to resolve it.