2008 Jeep Patriot Owner's Manual - Page 351

MAINTAINING YOUR VEHICLE 349 ONBOARD DIAGNOSTIC SYSTEM - OBD II Your vehicle is equipped with a sophisticated Onboard Diagnostic system called OBD II. This system monitors the performance of the emissions, engine, and automatic transaxle control systems. When these systems are operating properly, your vehicle will provide excellent performance and fuel economy, as well as engine emissions well within current government regulations. If any of these systems require service, the OBD II system will turn on the Malfunction Indicator Light (MIL). It will also store diagnostic codes and other information to assist your service technician in making repairs. Although your vehicle will usually be drivable and not need towing, see your authorized dealer for service as soon as possible. CAUTION! • Prolonged driving with the MIL on could cause further damage to the emission control system. It could also affect fuel economy and drivability. The vehicle must be serviced before any emissions tests can be performed. • If the MIL is flashing while the engine is running, severe catalytic converter damage and power loss will soon occur. Immediate service is required. Loose Fuel Filler Cap Message 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 7