P2A82

Code

Generic P — Powertrain

Alternative Fuel Pump A Compression Stroke Valve Control Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 23 EN: 33 RU: 16

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Read and record freeze-frame data and pending codes; note operating conditions
Visually inspect wiring and connectors at the pump/solenoid and PCM for damage, corrosion, or pushed-out pins
Check relevant fuses and relays for correct rating and continuity
Measure battery voltage and verify proper ground at pump and PCM grounds
Backprobe the control connector and measure voltage with key ON and during cranking/operation
Unplug the solenoid connector: check whether the code clears or behavior changes

Key ON, engine OFF: control line should not be held at persistent battery voltage when PCM is not commanding
When commanded, PCM typically modulates the valve via a low-side drive (pulsed ground) or PWM — expect switching behavior rather than a solid high
A ‘high’ fault means the control line is measuring higher than the PCM’s expected level (near battery voltage) when it should be low or switching
Use an oscilloscope to confirm frequency and duty cycle of the PWM signal rather than relying only on a DC multimeter

Retrieve freeze-frame and attempt to re-create the fault conditions. Record exact operating state when code set.
Perform a visual inspection of the pump, valve solenoid connector, wiring harness, and PCM connector for damage or corrosion.
Check fuses/relays related to the alternative fuel pump circuit; replace if suspect.
With connector plugged, backprobe the control wire. With key ON engine OFF measure voltage; note if it is held at battery voltage or shows switching.
Unplug the solenoid. If the control line voltage changes or the code clears after driving cycle, suspect the solenoid or wiring to the pump.
Check continuity between the solenoid connector and the PCM pin; check for short to battery (infinite resistance to battery positive indicates no short).
If a short to battery is present, isolate by inspecting harness sections and repairing insulation, connectors or routing.
If wiring and connectors are good and solenoid is known good (or swap-tested), suspect PCM or pump control module driver and consider module testing/replacement per manufacturer procedures.
After repairs, clear codes and road test to confirm fault does not return; verify normal signal parameters with scanner or oscilloscope.

Wiring shorted to constant 12 V (pinched harness near engine or pump)
Corroded connector allowing resistance/voltage drop and false reading
Failed solenoid coil with internal short or wiring fault inside the pump assembly
PCM or dedicated pump module driver failed and sourcing voltage onto the circuit