GMC Yukon 2021 Owner's Manual page 388

Service and Maintenance 387
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. Check engine air filter life percentage and status.
Change engine air filter, if needed.
Replace passenger compartment air filter. (1)
Inspect evaporative control system. (2)
If the vehicle is not equipped with the engine air filter life
system, replace engine air cleaner filter. (3)
Change transfer case fluid, if equipped with 4WD. (4)
Replace spark plugs. Inspect spark plug wires and/or boots.
Drain and fill engine cooling system. (5)
Visually inspect accessory drive belts. (6)
Replace brake fluid. (7)
Replace front and rear wiper blades. (8)
Replace hood and/or body lift support gas struts. (9)
Replace air conditioning desiccant. (10)