Code result
P0499
Evaporative Emission System Vent Valve Control Circuit High
Moderate severity
What it means
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.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Control line open
highOne of the most commonly reported causes for this code — check this first.
Control line shorted to supply
mediumA plausible cause — test and verify before replacing parts.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Related help
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