P1348
FordFuel Level Sensor B Circuit Low
The vehicle detects a low signal in the Fuel Level Sensor B circuit. The sensor reports fuel level, so the gauge or estimated remaining range may be inaccurate. A low circuit signal does not mean the tank is low, and this code alone does not prove the sensor has failed.
⚠️ Before You Begin (Safety First)
Do not rely on the fuel gauge or remaining-range estimate until the fault is diagnosed; refuel earlier than usual to reduce the chance of running out. If you smell fuel or see fuel leaking, stop in a safe place and have the vehicle checked. This code alone does not establish that fuel is leaking.
Common Symptoms
- Fuel gauge may read incorrectly, fluctuate, or fail to reflect the actual fuel level because the reported signal is inaccurate.
- Remaining-range estimates may be unreliable if they use the affected fuel-level reading.
- The vehicle may run out of fuel unexpectedly if the gauge indicates more fuel than is actually in the tank.
- There may be no noticeable symptoms apart from a warning light or stored diagnostic code.
Common Causes
- Fuel Level Sensor B may have an internal electrical fault.
- Wiring in the Sensor B circuit may be damaged, shorted, or otherwise unable to carry the expected signal.
- A loose, corroded, or damaged connector or ground may interfere with the circuit.
- A fault in a related control-module input or circuit may cause the low signal reading.
Diagnostic Steps
- Check the fuel level using a recent fill-up or other reliable information, and do not assume the gauge is accurate.
- Note whether the gauge or range estimate is erratic or inconsistent; this can help describe the fault during diagnosis.
- With the vehicle safely parked and switched off, visually inspect only accessible Sensor B circuit wiring and connectors for obvious damage or looseness. Do not reach into the fuel tank or disconnect components around fuel vapors.
- Have a scan tool read the stored code and available fuel-level data. Compare the Sensor B reading with the gauge and other available readings.
- If the fault remains, have the circuit tested using vehicle-specific service information before replacing the sensor or other parts.
When to Call a Professional
Use a scan tool to compare Fuel Level Sensor B data with the gauge and other available fuel-level readings. Check the applicable wiring diagram and test the circuit, connectors, grounds, sensor, and control-module inputs as appropriate for the vehicle. Confirm the fault before replacing parts; exact procedures depend on model, year, and engine.
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Commonly Asked Questions
Does this code mean the tank is low on fuel?
No. It indicates a low signal in the Fuel Level Sensor B circuit, not a confirmed low fuel quantity.
Does P1348 prove the fuel level sensor needs replacement?
No. Wiring, connectors, grounds, or a related control-module circuit can also cause a low signal. Testing is needed before replacing parts.
Can I keep driving with this code?
The code may not affect how the engine runs, but the fuel gauge or range estimate may be unreliable. Refuel early and arrange diagnosis; stop safely if you smell fuel or see a leak.
What is the difference between Sensor B and Sensor A?
The code specifically identifies the Sensor B circuit. Its exact arrangement and location depend on the vehicle, so use model-, year-, and engine-specific service information rather than assuming it is a particular sender or tank location.
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