2007 Mercury Grand Marquis Owner Guide 2nd Printing - Page 248

Maintenance and Specifications Do not make any unauthorized changes to your vehicle or engine. By law, vehicle owners and anyone who manufactures, repairs, services, sells, leases, trades vehicles, or supervises a fleet of vehicles are not permitted to intentionally remove an emission control device or prevent it from working. Information about your vehicle's emission system is on the Vehicle Emission Control Information Decal located on or near the engine. This decal identifies engine displacement and gives some tune up specifications. Please consult your Warranty Guide for complete emission warranty information. On board diagnostics (OBD-II) Your vehicle is equipped with a computer that monitors the engine's emission control system. This system is commonly known as the On Board Diagnostics System (OBD-II). The OBD-II system protects the environment by ensuring that your vehicle continues to meet government emission standards. The OBD-II system also assists your authorized dealer in properly servicing your vehicle. When the indicator illuminates, the OBD-II system has detected a malfunction. Temporary malfunctions may cause the indicator to illuminate. Examples are: 1. The vehicle has run out of fuel-the engine may misfire or run poorly. 2. Poor fuel quality or water in the fuel-the engine may misfire or run poorly. 3. The fuel cap may not have been securely tightened. See Fuel filler cap in this chapter. 4. Driving through deep water-the electrical system may be wet. These temporary malfunctions can be corrected by filling the fuel tank with good quality fuel, properly tightening the fuel cap or letting the electrical system dry out. After three driving cycles without these or any other temporary malfunctions present, the indicator should stay off the next time the engine is started. A driving cycle consists of a cold engine startup followed by mixed city/highway driving. No additional vehicle service is required. indicator remains on, have your vehicle serviced at the first If the available opportunity. Although some malfunctions detected by the OBD-II may not have symptoms that are apparent, continued driving indicator on can result in increased emissions, lower fuel with the economy, reduced engine and transmission smoothness, and lead to more costly repairs. 248 2007 Grand Marquis (grn) Owners Guide (post-2002-fmt) USA (fus)