GMC 2010 Yukon XL Denali Owner's Manual page 512

Once a Year
Starter switch check. See Owner Checks and
Services on page 7 9.
Parking brake and automatic transmission P (Park)
mechanism check. See Owner Checks and
Services on page 7 9.
Automatic transmission shiftlock control system
check. See Owner Checks and Services on
page 7 9.
Ignition transmission lock check. See Owner
Checks and Services on page 7 9.
Hood and liftgate gas strut support service.
Visually inspect gas strut for signs of wear,
corrosion, cracks, loss of lubricant, or other
damage. Check the hold open ability of gas strut.
Replace as necessary with genuine parts from
your dealer/retailer.
Engine cooling system and pressure cap pressure
check. Radiator and air conditioning condenser
outside cleaning. See Cooling System on
page 6 26.
Exhaust system and nearby heat shields
inspection for loose or damaged components.
Accelerator pedal check for damage, high effort,
or binding. Replace if needed.
7-6
First Engine Oil Change After Every
40 000 km/25,000 Miles
Fuel system inspection for damage or leaks.
First Engine Oil Change After Every
80 000 km/50,000 Miles
Engine air cleaner filter replacement. See Engine
Air Cleaner/Filter on page 6 20.
Automatic transmission fluid change (severe
service) for vehicles mainly driven in heavy city
traffic in hot weather, in hilly or mountainous
terrain, when frequently towing a trailer, or used for
taxi, police, or delivery service. See Automatic
Transmission Fluid on page 6 22.
Transfer case fluid change (severe service) for
vehicles mainly driven when frequently towing a
trailer, or used for taxi, police, or delivery 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.