Ford 2006 Expedition Owner's Manual page 334

Maintenance and Specifications
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). This 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 your 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.
3. The fuel cap may not have been securely tightened. See Fuel filler
cap in this chapter.
These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly tightening the fuel cap. After three
driving cycles without these or any other temporary malfunctions
present, the indicator should turn off—A driving cycle consists of a
cold engine startup followed by mixed city/highway driving. No additional
vehicle service is required.
If the indicator remains on, have your vehicle serviced at the first
available opportunity.
Readiness for Inspection/Maintenance (I/M) testing
In some localities, it may be a legal requirement to pass an I/M test of
the on-board diagnostics system. If your indicator is on, refer to
the description in the Warning lights and chimes section of the
Instrument Cluster chapter. Your vehicle may not pass the I/M test with
the indicator on.
If the vehicle's powertrain system or its battery has just been serviced,
the on-board diagnostics system is reset to a "not ready for I/M test"
condition. To ready the on-board diagnostics system for I/M testing, a
minimum of 30 minutes of city and highway driving is necessary as
described below:
• First, at least 10 minutes of driving on an expressway or highway.
• Next, at least 20 minutes driving in stop-and-go, city-type traffic with
at least four idle periods.
334
2006 Expedition (exd)
Owners Guide (post-2002-fmt)
USA (fus)