What it means
The alternative fuel pump A compression stroke valve control circuit is open or has a fault.
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 alternative-fuel pump A compression stroke valve is controlled through an electrical circuit so the pump can build pressure during its compression stroke. P2A7F sets when the control circuit is open or otherwise has a fault, such as a broken control wire, an open valve coil, or a connector pin pushed back from its terminal.
Common causes
Most likely first.
- Open in valve control wire
- Open valve coil
- Pin pushed back out of connector body
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
- Save freeze-frame data and check for related alternative-fuel pump codes to see whether the fault appeared during starting or high-load operation.
- Inspect pump A's compression stroke valve connector for a pushed-back pin, a loose fit, corrosion, or harness damage.
- Use the wiring diagram to check the valve control circuit for continuity and an open between the valve and control module.
- Test the compression stroke valve coil and compare its result with the manufacturer's specification.
- If the valve and wiring pass, check the circuit's connection at the control module using the manufacturer's diagnostic procedure.
Common fixes
- Reseat a pushed-back pin and secure the compression stroke valve connector.
- Repair an open or damaged wire in pump A's valve control circuit.
- Replace the compression stroke valve if its coil is open.
- Repair a verified poor terminal connection at the control module.
Can I keep driving?
A faulty compression stroke valve circuit can cause long cranking, a no-start, stalling, or power loss under load. Avoid driving if the engine stalls or cannot maintain power, and do not rely on the vehicle for demanding trips.
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.