P2A72Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2A72 is set when the control circuit of the hydraulic fuel pump select valve reads lower than expected for the commanded state. On a low-side driver this typically means the control wire is shorted to ground, so the valve coil may stay energised; on a high-side driver a short to ground or a shorted coil pulls the output down and may trip its protection. Either way the controller can no longer trust which LNG tank pump is being driven. Westport's patented system relies on knowing the valve position to assign hydraulic pressure readings to the right pump, so tank selection and empty-tank detection become unreliable. No manufacturer documents P2A72. Measure coil resistance and check the harness for chafing against the chassis.
- What you may notice
- Check engine light on
- Select valve stays switched, one tank pump runs permanently
- Gas supply interrupted when the active tank runs empty
- Likely causes
- LikelyControl wire chafed on the frame and shorted to ground
- PossibleSelect valve coil with shorted turns
- RareWater in the connector bridging to ground
- 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: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.