Mustang V8-4.6L (2009)
Fuel Filler Cap Warning Indicator: Description and Operation
Engine Control Components
Check Fuel Cap Indicator
The check fuel cap indicator is a communications network message sent by the PCM. The PCM sends the message to illuminate the lamp when the
strategy determines there is a concern in the EVAP system due to the fuel filler cap or capless fuel tank filler pipe not being sealed correctly. This is
detected by the inability to pull vacuum in the fuel tank after a fueling event.
