Malfunction Indicator Lamp - Hummer 2008 H2 Owner's Manual

Malfunction Indicator Lamp

Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation
of the fuel, ignition, and emission control systems.
It makes sure that emissions are at acceptable
levels for the life of the vehicle, helping to produce
a cleaner environment.
Malfunctions often are indicated by the system before
any problem is apparent. This can prevent more serious
damage to your vehicle. This system is also designed
to assist your service technician in correctly diagnosing
any malfunction.
3-42
The check engine light
comes on to indicate
that there is an OBD II
problem and service
is required.
Notice: If you keep driving your vehicle with
this light on, after a while, the emission controls
might not work as well, your vehicle's 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 your warranty.
Notice: Modifications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original
tires with other than those of the same Tire
Performance Criteria (TPC) can affect your vehicle's
emission controls and can cause this light to
come on. Modifications to these systems could
lead to costly repairs not covered by your warranty.
This could also result in a failure to pass a
required Emission Inspection/Maintenance test.
See Accessories and Modifications on page 5-3.