P2A84 — Alternative Fuel Pump B Compression Stroke Valve Control Circuit Range/Performance
The control circuit of the compression stroke valve in alternative fuel pump B reports a control circuit range/performance condition. Pump compression stroke cannot be commanded as expected.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Alt fuel pump b compression stroke valve
- Wiring harness
- Afcm
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Valve responds slower than expected
- High-resistance contact in connector
- Sensor element aged beyond calibration window
Possible symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- Reduced-power or limp mode may occur
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.