P2A43Alternative Fuel Tank B Pressure Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2A43 is stored when the signal of the tank B pressure sensor drops below its lower electrical limit, a level that no real tank pressure produces. The usual reasons are a signal wire grounded against the frame, a missing 5 V reference or an internal short in the sensor. For the tank A sensor, TransEco's AFCM list puts exactly these faults under its Low code, with a substitute value of 3600 psi and the lamp switched on in both dedicated and bi-fuel setups. Because a low signal looks like an empty cylinder, the gauge may drop to zero and tank B may be locked out although it still holds gas. No manufacturer documents P2A43 itself. Ford's 2014 Boss 302S table carries the tank A version P01A0 as a lamp code, a sign that the family is treated as emission-relevant.
- What you may notice
- Check engine light
- Gauge drops to empty for tank B
- Less usable gas range
- Likely causes
- LikelySignal wire shorted to ground
- Possible5 V reference open or pulled down by another sensor
- PossibleInternal short in the tank B sensor
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.