P2A80 Alternative Fuel Pump A Compression Stroke Valve Control Circuit Range/Performance

P2A80 concerns the compression stroke valve of pump A when its circuit is intact but the outcome of a command does not match. In the patented multi-element design, the time the solenoid holds the spool in the fill position sets the stroke, and a shorter command yields a partial stroke; the controller therefore expects a defined gain in gas pressure or hydraulic load per activation. If pump A contributes clearly less than its partners, or the spool reacts late, a sticking spool, varnished oil or a weak return spring are likely. Caterpillar also stresses that hydraulic pressure during the stroke must be held within tight limits to keep the LNG from vaporizing. No manufacturer publishes P2A80 or its test.

Likely causes

Symptoms

• Warning lamp after several drive cycles
• Uneven gas pressure and slight power loss

Repair estimate

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

Parts involved

Related codes

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