P2A45 Alternative Fuel Tank B Pressure Sensor Circuit Intermittent/Erratic

P2A45 completes the tank B pressure group with the case that the other codes miss: the signal is mostly fine but jumps or drops out for moments, faster than any real gas pressure could change. Typical culprits are a plug that loses contact on rough roads, a wire rubbed through along the frame rail or a sensor with a cracked solder joint. Because the fault comes and goes, a single clean reading proves nothing. How such faults age out is described in Ford's material on its 2003 bi-fuel CNG trucks: once the condition stops, the lamp goes dark three trips later and the stored code disappears after forty. No manufacturer documents P2A45 itself; the logic follows the tank A counterpart P01A2 and the CARB rules for input components. Wiggle the harness while watching live data.

Likely causes

Symptoms

• Check engine light that comes and goes
• Gas gauge flickering or jumping
• Occasional unexpected switch to petrol on bi-fuel vehicles

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, static.nhtsa.gov.