Powertrain, generic (extended)

P2A87 Alternative Fuel Pump C Compression Stroke Valve Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2A87 covers the control circuit of the compression stroke valve on alternative fuel pump C, reporting an open or otherwise unusable circuit. A third pump valve only exists on systems with at least three separately switched pumping units. Caterpillar's patent US10060421B2 is such a case: it describes six elements arranged around one pump body, allows an odd number as well, and fires each through its own solenoid in a timed sequence. If valve C drops out, the sequence has a gap, delivery becomes uneven and the controller has to fire the others more often to hold gas pressure. No manufacturer publishes P2A87 or assigns the letter C. Check coil resistance and terminals, and whether codes for valves A or B are present as well.

Likely causes

Open wire or loose connector at valve C
Solenoid coil of valve C open
Output stage for valve C faulty

Symptoms

  • Warning lamp on
  • Uneven gas pressure, slight power loss 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

P2A88P2A89P2A8AP2A7FP2A83

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