GMC Sierra Limited 1500 2019 Owner's Manual page 440

Service and Maintenance 439
Maintenance Schedule
Additional Required
Services - Severe
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)
Replace engine air cleaner filter. (2)
Inspect evaporative control system. (3)
Replace spark plugs. Inspect spark plug wires.
Change automatic transmission fluid and filter.
For GVW under 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)
For GVW over 3 900 kg (8,600 lb), 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)
Replace windshield wiper blades (8)
Replace hood and/or body lift support gas struts.