Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
See Gasoline Octane on page 266. Poor fuel
quality will cause your engine not to run as
efficiently as designed. You may notice this as
stalling after start-up, stalling when you put the
vehicle into gear, misfiring, hesitation on
acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is warmed
up.) This will be detected by the system and cause
the light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at
least one full tank of the proper fuel to turn the
light off.
If none of the above steps have made the light turn
off, your dealer can check the vehicle. Your dealer
has the proper test equipment and diagnostic tools
to fix any mechanical or electrical problems that
may have developed.
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have
or may begin programs to inspect the emission
control equipment on your vehicle. Failure to pass
this inspection could prevent you from getting a
vehicle registration.
Here are some things you need to know to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
Check Engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that
critical emission control systems have not been
completely diagnosed by the system. The vehicle
would be considered not ready for inspection. This
can happen if you have recently replaced your
battery or if your battery has run down. The
diagnostic system is designed to evaluate critical
emission control systems during normal driving.
This may take several days of routine driving. If you
have done this and your vehicle still does not pass
the inspection for lack of OBD system readiness,
your GM dealer can prepare the vehicle for
inspection.
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