GMC 2008 Acadia - Manual (Page 195)

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
See Gasoline Octane on page 5-6. Poor fuel quality
causes the engine not to run as efficiently as
designed. You might 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 might 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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to fix any mechanical or electrical
problems that might have developed.
Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have
or might 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 the
battery or if the battery has run down. The diagnostic
system is designed to evaluate critical emission
control systems during normal driving. This can 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 dealer/retailer
can prepare the vehicle for inspection.
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