GMC 2007 Automobile User Manual


 
Malfunction Indicator Lamp
Check Engine Light
Your vehicle has a
computer which
monitors operation
of the fuel, ignition,
and emission control
systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for
the life of the vehicle, helping to produce a cleaner
environment. The Check Engine light comes on
to indicate that there is a problem and service is
required. Malfunctions often will be indicated by the
system before any problem is apparent. This may
prevent more serious damage to your vehicle. This
system is also designed to assist your service
technician in correctly diagnosing any malfunction.
Notice: If you keep driving your vehicle with
this light on, after awhile, your emission
controls may not work as well, your fuel
economy may not be as good, and your engine
may not run as smoothly. This could lead to
costly repairs that may not be covered by your
warranty.
Notice: Modifications made to the engine,
transaxle, exhaust, intake, or fuel system of
your vehicle or replacement tires that do not
match your vehicle’s original tires can affect
your vehicle’s emission controls and may cause
this light to come on. Modifications to these
systems could lead to costly repairs not
covered by your warranty. This may also
result in a failure to pass a required Emission
Inspection/Maintenance test. See Accessories
and Modifications on page 264.
When the ignition is on, this light should come on
and should go out after a few seconds as a check to
show you it is working. If the light does not come
on, have it repaired.
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