Ford 2000 Mustang, Owner'S Manual

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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 high quality fuel of the
recommended octane 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.
Instrumentation
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