P01AC — Alternative Fuel Tank Temperature Sensor Circuit Low

P01AC reports an electrical input below the calibrated limit for the alternative-fuel tank temperature sensor circuit. It does not establish that the real tank temperature is low or that the sensor is defective.

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: P01AC-00, P01AC00, PO1AC (some scan tools add the fault-type byte, e.g. -00).