P2A40 — Alternative Fuel System - Injector Leakage to Rail Detected
The AFCM detects pressure decay in the alternative fuel rail consistent with injector leakage. Even with all injectors commanded closed, fuel flows back into the rail.
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 injectors
- Alt fuel rail
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Injector seat worn - leaks closed
- Injector seal aged - external leak path
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.