Exhaust leaks may result in entry of harmful and potentially
lethal fumes into the passenger compartment.
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 yourWarranty Guidefor 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 theService
engine soon
indicator illuminates, the OBD-II system has detected
a malfunction. Temporary malfunctions may cause theService engine
soon
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. SeeFuel filler
capin 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, theService engine soon
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.
If theService engine soon
indicator remains on, have your vehicle
serviced at the first available opportunity. Although some malfunctions
2008 F-150(f12)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
369
