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P04EA code meaning

EVAP System Small Leak Detected - Fuel Tank Side

Powertrain system Generic code P04xx codes Check engine light

What P04EA 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. P04EA reports a small leak (0.040 in) in the tank section – tank, filler neck, cap and lines up to the tank valve. No manufacturer document available to us names this code; the description follows CARB and the Ford patent.

P04EA at a glance

  • Check engine lightYes, usually on
  • Emissions testCan fail
  • Limp modeNot expected
  • Repair difficultyMedium, DIY possible
  • Typical labor0.2 to 3 hours
  • Clears after repairAfter a drive cycle

Symptoms of P04EA

  • Check engine light on
  • Possibly check fuel cap message or slight fuel smell
  • No change in driving

Common causes of P04EA

  • Most likelyFuel cap or seal leaking or not closed properly (tether trapped)
  • PossibleFiller neck or tank vent line leaking
  • PossibleSender or pump flange seal leaking
  • Less likelyTank valve or tank pressure sensor faulty

Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.

Parts involved

Fuel tankFuel capFuel tank isolation valveFuel tank pressure sensor

What each part of P04EA means

PPowertrain system: engine, fuel system, ignition, emissions and transmission.
0Generic code: it means the same on every make (SAE standard).
4Area: auxiliary emission controls (catalytic converter, EGR, EVAP).
EAThe exact fault in that area.

What to do next

  • Note P04EA 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 P04EA

What does P04EA mean?

P04EA means "EVAP System 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 P04EA?

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 P04EA fail an emissions test?

Yes, it can. P04EA 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 P04EA to fix?

Difficulty: medium. A typical repair takes 0.2 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.

Will P04EA 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.

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Technical content: OBDex open OBD-II database (public domain, CC0), checked 11 Oct 2026, edited for US drivers by the VinGear team.
Technical sources for P04EA