Fault Family System: Powertrain (P-Codes) 12 SAE Codes

Alt Fuel Pump Compression Valve

Diagnostic & Technical Explanation

Code P2A7F (Alternative Fuel Pump A Compression Stroke Valve Control Circuit/Open) covers the compression-stroke control valves (pump A, B, or C) that time liquid alternative fuel delivery into the injection pump's compression stroke. The ECM detects an open circuit, out-of-range voltage, or a performance deviation while driving the valve. A failed valve coil, fuel varnish sticking the valve plunger, or damaged control wiring at the pump harness connector are the typical causes.

These 12 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 12 times.

Codes in this family (12)

Code	Definition	Repair coverage
P2A7F	Alternative Fuel Pump A Compression Stroke Valve Control Circuit/Open	4 ranked fixes
P2A80	Alternative Fuel Pump A Compression Stroke Valve Control Circuit Range/Performance	4 ranked fixes
P2A81	Alternative Fuel Pump A Compression Stroke Valve Control Circuit Low	4 ranked fixes
P2A82	Alternative Fuel Pump A Compression Stroke Valve Control Circuit High	4 ranked fixes
P2A83	Alternative Fuel Pump B Compression Stroke Valve Control Circuit/Open	4 ranked fixes
P2A84	Alternative Fuel Pump B Compression Stroke Valve Control Circuit Range/Performance	4 ranked fixes
P2A85	Alternative Fuel Pump B Compression Stroke Valve Control Circuit Low	4 ranked fixes
P2A86	Alternative Fuel Pump B Compression Stroke Valve Control Circuit High	4 ranked fixes
P2A87	Alternative Fuel Pump C Compression Stroke Valve Control Circuit/Open	4 ranked fixes
P2A88	Alternative Fuel Pump C Compression Stroke Valve Control Circuit Range/Performance	4 ranked fixes
P2A89	Alternative Fuel Pump C Compression Stroke Valve Control Circuit Low	4 ranked fixes
P2A8A	Alternative Fuel Pump C Compression Stroke Valve Control Circuit High	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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