Fuel Cap Warning Message
The PCM detects a loose or missing fuel fill cap as an evaporative system leak, and it alerts the driver by showing a warning message in the gauge display.
The first time a leak is detected a TIGHTEN FUEL CAP message appears on the gauge display (A). To scroll to another message, press the select/reset button. The TIGHTEN FUEL CAP message appears each time you restart the engine until the system turns the message off. Turn the engine off, then replace or tighten the fuel fill cap until it clicks at least once.