P01B1
Alternative Fuel Tank A Level Sensor Circuit Low
Generic OBD-II
Common symptoms
What you'll notice
- Check the wiring and connections of the alternative fuel tank level sensor
- Inspect and clean the fuel tank to ensure there is no debris or contamination affecting the sensor
- Replace the alternative fuel tank level sensor if it is found to be faulty or damaged
- Update the vehicle's software or firmware related to the alternative fuel system
Common causes
Most likely first
- Faulty or malfunctioning alternative fuel tank level sensor
- Low fuel level in the alternative fuel tank
- Wiring or connection issues in the alternative fuel tank level sensor circuit
- Faulty or malfunctioning engine control module (ECM)
- Sensor circuit or ECM software issue
How to diagnose & fix
Work through it in order
- Dashboard warning light indicating a fuel tank issue
- Inaccurate fuel level readings on the fuel gauge
- Engine stalling or hesitating during acceleration
- Difficulty starting the vehicle or motorcycle
- Poor fuel efficiency
Read & clear P01B1 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.