P2A7FAlternative Fuel Pump A Compression Stroke Valve Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Hydraulically driven LNG pumps use solenoid valves to admit high-pressure oil to the drive side for the compression stroke and to vent it again for refilling. Caterpillar's patent US10060421B2 gives each of its six pumping elements, other counts being possible, a solenoid pilot that moves a spool between fill and drain positions; the controller sets timing and length of every stroke this way. P2A7F reports that pump A's compression stroke valve has an open or otherwise faulty control circuit. The valve then stays in its spring position and pump A no longer delivers. Which element or tank pump carries the letter A is not published, and neither is P2A7F itself. Check coil resistance and connector first.
- What you may notice
- Warning lamp on
- Reduced LNG delivery and lower power
- Gas pressure drops under load
- Likely causes
- LikelyOpen wire or loose connector at valve A
- PossibleSolenoid coil of valve A burnt open
- RareOutput stage in the control module faulty
- 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 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.