OBD-II code · Powertrain (generic)
P04B0 Refueling Vapor Control Valve Circuit Open
The refueling vapor control valve - typically part of the ORVR or capless fueling system - has an open control circuit. The valve directs fuel vapor from the tank into the canister during refueling and must open when the fuel filler is opened. Without it, vapor escapes during refueling and the system fails leak diagnostics.
Is it safe to drive with P04B0?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in harness or solenoid winding
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.8–1.8 h
- Emissions test
- Likely to fail
- Parts involved
- Refueling Vapor Valve, Vapor Canister, Fuel Filler Assembly
Related codes
- P04ADEVAP System Purge Control Valve B Circuit High
- P04AEEVAP System Purge Control Valve B Performance Stuck Open
- P04AFEVAP System Purge Control Valve B Stuck Closed
- P04B1Refueling Vapor Control Valve Circuit Low
- P04B2Refueling Vapor Control Valve Circuit High
- P04B3Refueling Vapor Control Valve Performance Stuck Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.