P04EEEVAP System Very Small Leak Detected - Fuel Tank Side
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Hybrids with a sealed fuel tank have a valve separating the tank from the charcoal canister and its vent side. CARB allows such sections to be leak-checked separately with their own codes; a Ford patent checks the tank side via tank pressure with the valve closed and the canister side with a leak check module. Conventional systems report the same leak as P0442, P0455 or P0456. P04EE reports a very small leak (0.020 in) in the tank section, usually checked with the engine off. Stellantis documents it on the Jeep Wrangler 4xe – cap, tether or filler tube, with a scan-tool leak test before replacing parts – and Ford on the C-Max, Fusion and MKZ hybrids and Energi of 2013–17, together with P0456 and P0457, fixed by a tighter purge valve and software.
- What you may notice
- Check engine light on
- Check fuel cap message
- No change in driving
- Likely causes
- LikelyFuel cap seal deformed or dirty, tether trapped
- PossiblePurge valve not sealing (Ford hybrids) – plus software
- PossibleLeaking quick connector or vent line at the tank
- RareHairline crack in tank lines or flange seal
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €0 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.