Ford 1999 Wagon-Econoline Owner's Manual page 9

government emission standards. The OBD II system also assists the
service technician in properly servicing your vehicle.
The Service Engine Soon indicator light illuminates when the ignition is
first turned to the ON position to check the bulb. If it comes on after the
engine is started, one of the engine's emission control systems may be
malfunctioning. The light may illuminate without a driveability concern
being noted. The vehicle will usually be drivable and will not require
towing.
What you should do if the Service Engine Soon light illuminates
Light turns on solid:
This means that the OBD II system has detected a malfunction.
Temporary malfunctions may cause your Service Engine Soon light 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 properly installed and securely
tightened.
These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly installing and securely tightening
the gas cap. After three driving cycles without these or any other
temporary malfunctions present, the Service Engine Soon light 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 Service Engine Soon light remains on, have your vehicle serviced
at the first available opportunity.
Light is blinking:
Engine misfire is occurring which could damage your catalytic converter.
You should drive in a moderate fashion (avoid heavy acceleration and
deceleration) and have your vehicle serviced at the first available
opportunity.
Under engine misfire conditions, excessive exhaust temperatures
could damage the catalytic converter, the fuel system, interior
floor coverings or other vehicle components, possibly causing a fire.
Instrumentation
9