Malfunction; Indicator Lamp; Malfunction Indicator Lamp - GMC Acadia 2011 Owner's Manual

5-18 Instruments and Controls

Malfunction

Indicator Lamp

A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors operation
of the fuel, ignition, and emission
control systems. It ensures that
emissions are at acceptable levels
for the life of the vehicle, helping to
produce a cleaner environment.
This light should come on when the
ignition is on, but the engine is not
running, as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer.
If the Malfunction Indicator Lamp
comes on and stays on while the
engine is running, this indicates that
there is an OBD II problem and
service is required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system assists
the service technician in correctly
diagnosing any malfunction.
Notice: If the vehicle is
continually driven with this
light on, after a while, the
emission controls might not
work as well, the vehicle fuel
economy might not be as good,
and the engine might not run
as smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty.
Notice: Modifications made to
the engine, transmission,
exhaust, intake, or fuel system
of the vehicle or the replacement
of the original tires with other
than those of the same Tire
Performance Criteria (TPC)
can affect the vehicle's emission
controls and can cause this
light to come on. Modifications
to these systems could lead to
costly repairs not covered by
the vehicle warranty. This could
also result in a failure to
pass a required Emission
Inspection/Maintenance test.
See Accessories and
Modifications on page 10 3.