P2A71Alternative Fuel Hydraulic Fuel Pump Select Valve Control Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2A71 concerns the function of the hydraulic fuel pump select valve rather than its wiring: the circuit is intact, but the system does not respond as expected after a switch command. In Westport's design the controller links the hydraulic pressure it measures to whichever pump the selector valve should be feeding; if the pressure pattern does not match the commanded pump, or the empty-tank logic sees no change after switching, the valve is probably sticking or leaking internally. Contaminated hydraulic oil, a worn spool or a weak solenoid are typical. Caterpillar's patent describes a related directional valve whose actuator is shifted once pressure sensors detect the stroke end. No manufacturer publishes P2A71 or its limits.
- What you may notice
- Check engine light on
- Tank changeover does not happen or happens late
- Uneven LNG levels between tanks
- Likely causes
- LikelyValve spool sticking due to contaminated hydraulic oil
- PossibleWorn valve leaking internally, flow reaches both pumps
- RareSolenoid force too low, for example from low supply voltage
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €200 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.