Malfunction Indicator Lamp - GMC 2005 Sierra 1500 Pickup Owner's Manual

The following situations can cause the transmission to
operate at higher temperatures:
•
Towing a trailer
•
Hot outside air temperatures
•
Vehicle overloading
•
Hauling a large or heavy load
•
Low transmission fluid level
•
High transmission fluid level
•
Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, see Scheduled Maintenance
on page 6-4 for the proper transmission maintenance
intervals.
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Malfunction Indicator Lamp

Check Engine Light
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The check engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice: If you keep driving your vehicle with this
light on, after awhile, your emission controls
may not work as well, your fuel economy may not
be as good, and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition, and emission
control systems.