Powertrain
generic / SAE
P04B3
Refueling Vapor Control Valve Performance Stuck Open
The refueling vapor control valve is stuck open. Vapor pathways meant to be closed except during refueling stay permanently open, distorting EVAP leak diagnostics and allowing vapor flow even with the fuel cap closed.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / B3
Possible causes
- Valve stuck open due to debris or weak spring high
- Carbon or debris buildup preventing free movement low
- Component wear with age - mechanical play low
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 120–400 €
- Estimated time: 0.8–1.8 h
- Component: refueling vapor valve
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012