User Guide

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.
To perform a Check Engine light bulb check with the
keyless ignition, make sure the transmitter fob is in the
passenger compartment. See Ignition Positions on
page 2-22. Press the bottom of the ACC button on the
instrument panel and hold the button down for five
seconds. The instrument panel, including the Check
Engine light, will light up and the ignition will be on, but
the engine will not start — if you press the bottom of
the ACC button only briefly, less than five seconds, the
accessory mode will be turned on, but not the ignition.
After the bulb check, be sure to press and release
the ACC button again to turn the ignition off and avoid
draining the vehicle’s battery.
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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