2007 Dodge Nitro Owner's Manual - Page 302

302 STARTING AND OPERATING NOTE: Tighten the gas cap about 1/4 turn until you hear one click. This is an indication that cap is properly tightened. If the gas cap is not tighten properly, the Malfunction Indicator Light will come on. Be sure the gas cap is tightened every time the vehicle is refueled. WARNING! A fire may result if gasoline is pumped into a portable container that is inside of a vehicle. You could be burned. Always place gas containers on the ground while filling. Loose Fuel Filler Cap Message If the vehicle diagnostic system determines that the fuel filler cap is loose, improperly installed, or damaged, a "CHECK GASCAP" message will be displayed in the EVIC (Electronic Vehicle Information Center). Refer to "Electronic Vehicle Information Center" in Section 4 of this manual. Tighten the fuel filler cap until a "clicking" sound is heard. This is an indication that the fuel filler cap is properly tightened. Refer to "Onboard Diagnostic System - OBDII" in Section 7 of this manual for more information. CAUTION! Damage to the fuel system or emission control system could result from using an improper fuel tank filler cap (gas cap). A poorly fitting cap could let impurities into the fuel system.