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 also lists engine displacement.
Please consult your warranty information 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 service engine soon indicator illuminates, the OBD-II
system has detected a malfunction. Temporary malfunctions
may cause the service 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 fill inlet may not have been properly closed. SeeEasy Fuel®
No Cap Fuel Systemin 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 closing the fuel fill inlet or letting the
electrical system dry out. After three driving cycles without these or any
other temporary malfunctions present, the service engine soon indicator
should stay off the next time the engine is started. A driving cycle
consists of a cold engine start-up followed by mixed city or highway
driving. No additional vehicle service is required.
If the service engine soon indicator remains on, have your vehicle serviced
at the first available opportunity. Although some malfunctions detected by
the OBD-II may not have symptoms that are apparent, continued driving
with the service engine soon indicator on can result in increased emissions,
lower fuel economy, reduced engine and transmission smoothness, and can
lead to more costly repairs.
Fuel and Refueling167
2014 05+ Mustang(197)
Owners Guide gf, 1st Printing, November 2012
USA(fus)
