Evaporative Emission Control System Vent Control Circuit Malfunction
Common Symptoms
- Check engine light on
- Fuel smell possible
- No drivability symptoms
- EVAP monitor may not complete
Most Likely Root Causes
- Faulty EVAP vent valve (stuck closed or open)
- Open or short in vent valve wiring
- Blocked vent valve filter
- PCM vent valve driver failure
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Severity / Derate Risk
Low.
Component Location
EVAP vent valve at charcoal canister, typically near fuel tank or in rear of engine bay.
Manufacturer Notes
Vent valve is normally open — it closes during EVAP monitor testing. A stuck-closed valve prevents EVAP monitor from running. Check for debris in vent filter.
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