What it means
The alternative fuel hydraulic fuel pump select valve control circuit signal is lower than expected.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The module controls the alternative-fuel hydraulic pump select valve through an electrical circuit and monitors the circuit signal. P2A72 sets when that control signal is lower than expected, which can result from a short to ground, a shorted valve coil, or poor connector contact.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in valve coil
- Connector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
How to diagnose it
- Capture freeze-frame data and related codes to determine whether the low circuit condition coincides with starting or pump-selection problems.
- Inspect the select-valve connector and control-wire routing for corrosion, pin damage, or a wire rubbed through to ground.
- Check connector terminal fit and condition, since corrosion or poor contact can lower the signal at the valve.
- Test the control wire for a short to ground and check the valve coil for an internal short using the wiring diagram and manufacturer's procedure.
- If wiring and coil checks pass, verify the module's control output using the manufacturer's diagnostic procedure.
Common fixes
- Clean and secure corroded or loose select-valve connector terminals.
- Repair a control wire shorted to ground or damaged harness section.
- Replace the select valve if its coil is internally shorted.
- Repair a confirmed module-side circuit fault following the manufacturer's procedure.
Can I keep driving?
Avoid demanding acceleration or continued driving if the engine stalls or loses power, since the valve may not be controlled reliably. Stop if the vehicle cannot maintain power safely.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.