P2AA2 — Alternative Fuel Return Line Insufficient Flow
The AFCM detects that the flow through the alternative fuel return line is below the expected minimum for the active operating mode. Restricted line, stuck valve, or pump output too low.
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 return line
- Alt fuel return line valve
- Alt fuel pump
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Return line restricted by debris
- Return line valve stuck closed
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- Reduced-power or limp mode may occur
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.