What it means
Fuel temperature sensor B signal below minimum. Shorted to ground or sensor open. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Fuel Temperature sensor B sends its fuel-temperature signal to the engine control module through a dedicated circuit. This code sets when the sensor B signal falls below the module’s expected range, commonly because the signal is shorted to ground, the sensor has failed, or a connector has poor contact.
Common causes
Most likely first.
- Signal wire shorted to ground
- Sensor failed
- Connector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Hard starting or rough running
- Reduced engine performance
- Fuel economy may worsen
How to diagnose it
- Check freeze-frame and live sensor B data to confirm the low reading and note whether it is fixed or intermittent.
- Identify sensor B using the vehicle service information, then inspect its connector for corrosion, moisture, loose fit, or pushed-back pins.
- Trace the sensor B harness for chafing or damage and check the signal wire for a short to ground using the wiring diagram.
- Test sensor B circuit continuity and its reference and ground connections according to the manufacturer’s procedure and specification.
- If the wiring and connector are sound, test fuel temperature sensor B against the manufacturer’s specification and replace it if it fails.
Common fixes
- Secure sensor B’s connector and clean or repair corroded or loose terminals.
- Repair the sensor B signal wire if it is shorted to ground or damaged.
- Repair a faulty reference or ground connection in the sensor B circuit.
- Replace fuel temperature sensor B if it produces a low signal despite a sound circuit.
Can I keep driving?
If the engine runs normally, cautious driving to arrange diagnosis is generally reasonable, but avoid extended trips if hard starting, rough running, or power loss occurs. The low sensor B input may affect engine control and fuel economy.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.