EVAP System Vent Valve Control Circuit High
Same as P0498 with the control line open or shorted to supply. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.
Affected components
- Evap vent valve
- Evap vent wiring
Common causes
- High likelihood: Control line open
- Medium likelihood: Control line shorted to supply
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.