P01B3: Alternative Fuel Tank A Level Sensor Circuit Intermittent/Erratic — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
The monitor reports a intermittent or erratic signal in the circuit for the alternative-fuel tank A level sensor. The circuit description does not identify a failed component; a high or low electrical input alone does not establish a physically high or low temperature or level. Confirm applicability and follow the actual vehicle's service procedure.
Affected system: Powertrain
Symptoms
- Warning light may illuminate
- Related system function may be impaired
- Vehicle-specific symptoms vary
Possible causes
- Fuel supply or pressure issue, restricted injector, actuator fault, connector or wiring damage
- Related wiring, connector, power or ground fault
- Vehicle-specific mechanical or control issue
What to check
- Record stored and pending codes and freeze-frame data
- Check fuel supply and pressure readings, electrical supply and ground, and the relevant injector or regulator circuit before replacing parts.
- Confirm measured values against the vehicle service information
- Retest under the conditions that set the code
- Check fuel supply and pressure readings, electrical supply and ground, and the relevant injector or regulator circuit before replacing parts.
- Repair the verified cause and confirm the code does not return
Also written as: P01B3-00, P01B300, PO1B3 (some scan tools add the fault-type byte, e.g. -00).