P2A81
Alternative Fuel Pump A Compression Stroke Valve Control Circuit Low
The control circuit of the compression stroke valve in alternative fuel pump A reports a control circuit low condition. Pump compression stroke cannot be commanded as expected.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
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
Common causes
Ordered by how often each turns out to be the cause.
- Control wire shorted to groundCommon
- Internal short in valve coilPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Alt Fuel Pump A Compression Stroke Valve
- Wiring Harness
- Afcm
P2A81 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.