Cadillac CT6 2017 Owner's Manual page 314

SERVICE AND MAINTENANCE 313
Maintenance Schedule
Additional Required Services -
Normal
Rotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. (1)
Replace passenger compartment air filter. (2)
Inspect evaporative control system. (3)
Replace engine air cleaner filter. (4)
Replace spark plugs. Inspect spark plug wires. (3.0L
Twin Turbo Engine)
Replace spark plugs. Inspect spark plug wires. (3.6L
Engine)
Drain and fill engine cooling system. (5)
Change transfer case fluid. (6)
Change front and rear axle fluid.
Visually inspect accessory drive belts. (7)
Replace brake fluid. (8)