Fuel Level Sensor 'B' Circuit Low

The fuel level sensor 'B' is designed to tell the computer how much fuel is in the tank. If it's not getting enough voltage (below 0.5 volts), the computer thinks the sensor is failing or there's a wiring issue.

The engine control unit (ECU) monitors the fuel level sensor 'B' voltage signal which should typically range from 0.5 volts (empty) to 4.5 volts (full). If the voltage reads below 0.5 volts, the ECU will trigger this code.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 11. Check the fuel level. Ensure there is ample fuel in the tank (at least 1/4 full). Decision: If low, refill and recheck code.
2. 22. Inspect the wiring and connector for sensor 'B'. Look for damage or corrosion. Decision: If damaged, repair or replace.
3. 33. Connect a multimeter to the fuel level sensor 'B'. Check the voltage output while varying the fuel level. Decision: If voltage remains below 0.5V regardless of fuel level, replace the sensor.
4. 44. If sensor is functioning, check the wiring for shorts to ground or open circuits before replacing the ECU.

• Faulty fuel level sensor 'B'
• Open or shorted wiring to the sensor
• Corroded or loose connector at the sensor or ECU
• Low fuel level or bad fuel quality

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