GMC 2010 Yukon XL Denali Owner's Manual page 513

Evaporative control system inspection. Check all
fuel and vapor lines and hoses for proper hook up,
routing, and condition. Check that the purge valve,
if the vehicle has one, works properly. Replace as
needed. An Emission Control Service. The U.S.
Environmental Protection Agency or the California
Air Resources Board has determined that the
failure to perform this maintenance item will not
nullify the emission warranty or limit recall liability
prior to the completion of the vehicle's useful life.
We, however, urge that all recommended
maintenance services be performed at the
indicated intervals and the maintenance be
recorded.
First Engine Oil Change After Every
160 000 km/100,000 Miles
Automatic transmission fluid change (normal
service). See Automatic Transmission Fluid on
page 6 22.
Transfer case fluid change (normal service).
Check vent hose at transfer case for kinks
and proper installation. Check to be sure vent
hose is unobstructed, clear, and free of debris.
During any maintenance, if a power washer is used
to clean mud and dirt from the underbody, care
should be taken to not directly spray the transfer
case output seals. High pressure water can
overcome the seals and contaminate the transfer
case fluid. Contaminated fluid will decrease the life
of the transfer case and should be replaced.
Spark plug replacement and spark plug wires
inspection. An Emission Control Service.
First Engine Oil Change After Every
240 000 km/150,000 Miles
Engine cooling system drain, flush, and refill,
cooling system and cap pressure check, and
cleaning of outside of radiator and air conditioning
condenser (or every 5 years, whichever occurs
first). See Engine Coolant on page 6 27.
An Emission Control Service.
Engine accessory drive belt inspection for fraying,
excessive cracks, or obvious damage and
replacement, if needed. An Emission Control
Service.
7-7