P2A72 code meaning
Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit Low
Powertrain system Generic code P2Axx codes Check engine light
What P2A72 means
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.
P2A72 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2A72
- Check engine light on
- Select valve stays switched, one tank pump runs permanently
- Gas supply interrupted when the active tank runs empty
Common causes of P2A72
- Most likelyControl wire chafed on the frame and shorted to ground
- PossibleSelect valve coil with shorted turns
- Less likelyWater in the connector bridging to ground
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Alt fuel hyd pump select valveWiring harnessAfcm
What each part of P2A72 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| 72 | The exact fault in that area. |
What to do next
- Note P2A72 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2A72
What does P2A72 mean?
P2A72 means "Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit Low". P2A72 is set when the control circuit of the hydraulic fuel pump select valve reads lower than expected for the commanded state. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A72?
Drive gently and only to a workshop. With P2A72 the car can go into limp mode (reduced power) to protect itself.
Will P2A72 fail an emissions test?
Yes, it can. P2A72 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2A72 to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P2A72 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.