After fuel is added, the vehicle diagnostic system can determine if the fuel filler cap is possibly loose or improperly installed. A “GASCAP” message will be displayed in the instrument cluster. Tighten the gas cap until a clicking sound is heard. This is an indication that the gas cap is properly tightened. Press the trip odometer “Reset” button to turn off the message. If the problem persists, the message will appear the next time the vehicle is started. This might indicate a damaged cap. If the problem is detected twice in a row, the system will turn on the “Malfunction Indicator Light (MIL).” Resolving the problem will turn the MIL light off.