P04EE code meaning
EVAP System Very Small Leak Detected - Fuel Tank Side
Powertrain system Generic code P04xx codes Check engine light
What P04EE means
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.
P04EE at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.1 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P04EE
- Check engine light on
- Check fuel cap message
- No change in driving
Common causes of P04EE
- Most 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
- Less likelyHairline crack in tank lines or flange seal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel tankFuel capEVAP purge valveFuel tank pressure sensor
What each part of P04EE means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| EE | The exact fault in that area. |
What to do next
- Note P04EE and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P04EE
What does P04EE mean?
P04EE means "EVAP System Very Small Leak Detected - Fuel Tank Side". Hybrids with a sealed fuel tank have a valve separating the tank from the charcoal canister and its vent side. It is a generic code, so it means the same on every make.
Is it safe to drive with P04EE?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P04EE fail an emissions test?
Yes, it can. P04EE is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P04EE to fix?
Difficulty: easy. A typical repair takes 0.1 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P04EE clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.