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.
Affected components
- Alt fuel return line
- Alt fuel return line valve
- Alt fuel pump
Common causes
- High likelihood: Return line restricted by debris
- Medium likelihood: 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
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.