Powertrain, generic (extended)

P2A8A Alternative Fuel Pump C Compression Stroke Valve Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2A8A indicates that pump C's compression stroke valve circuit sits higher than the commanded state allows, from an open coil, a broken wire or a short to the supply rail. The solenoid cannot shift the spool, which stays in the drain position, and element C never starts a compression stroke. Unlike the low fault P2A89, nothing stays pressurised; the element is simply missing from the firing sequence, which the controller covers by firing the remaining ones more often. When P2A8A appears together with P2A82 or P2A86, a shared supply or ground for all valves is more likely than three failed coils. No manufacturer documents P2A8A. Check the common feed and ground before replacing valve C.

Likely causes

Open coil or broken wire at valve C
Fault in the supply or ground shared by the pump valves
Control wire shorted to the supply rail

Symptoms

  • Warning lamp on
  • Uneven gas pressure at high load

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,500
Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

alt fuel pump c compression stroke valvewiring harnessafcm

Related codes

P2A87P2A88P2A89P2A82P2A86

References: law.cornell.edu, patents.google.com.