GMC Sierra Denali 2014 Owner's Manual page 373

Service and Maintenance 11-5
Maintenance Schedule
Additional Required
Services - Normal
Rotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed.
Replace passenger compartment air filter. (1)
Inspect evaporative control system. (2)
Replace engine air cleaner filter. (3)
Replace spark plugs. Inspect spark plug wires.
Change automatic transmission fluid. Change
filter if serviceable.
Change transfer case fluid, if equipped with
4WD. (4)
Drain and fill engine cooling system. (5)
Visually inspect accessory drive belts. (6)
Replace brake fluid. (7)