Powertrain
generic / SAE
P0446
Evaporative Emission Vent Control Circuit Malfunction
A fault in the EVAP vent valve circuit. The vent valve seals the canister against atmosphere during the leak test; without it, the test cannot pull a vacuum and may set false leak codes alongside.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / 46
Possible causes
- Vent valve seized or contaminated by water/dirt high
- Wiring or connector fault medium
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 40–250 €
- Estimated time: 0.3–1.5 h
- Component: evap vent valve
- Component: evap vent valve wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012