Powertrain, generic · Auxiliary emission controls
P04CC Fuel Fill Door Open Request Sensor/Switch Circuit Intermittent/Erratic
Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo
On plug-in hybrids with a sealed, pressurised tank, pressing the fuel button (open request) starts a refuelling mode: the module opens the tank valve, releases the pressure into the charcoal canister and only then unlocks the filler door via an electric actuator (Ford patent). P04CC means the button signal is sporadic or implausible – a bouncing button or a loose contact. No manufacturer document available to us uses this code; the description follows CARB's rules for input and output components and patents on the door actuator.
Likely causes
Loose contact between button and module
Fuel button worn or bouncing
Button ground poor
Module
Symptoms
- Fuel button has no effect, door does not open
- Refuelling system message in the instrument cluster
- Refuelling only via emergency release
Repair estimate
DifficultyEasyDIY possible
Parts and labour€20–200
Time0.3–1.5 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
fuel door open request switchswitch wiringengine control module
Related codes
References: law.cornell.edu, patents.google.com, mitsubishitechinfo.com.