See also:

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the v ...

Maintenance I
• Change engine oil and filter. See Engine Oil. An Emission Control Service. • Engine coolant level check. See Engine Coolant (4.6L Engine) or Engine Coolant (3.9L Engine). • Windshield wa ...

Checking Coolant
The vehicle must be on a level surface when checking the coolant level. Check to see if coolant is visible in the coolant surge tank. If the coolant inside the coolant surge tank is boiling, do not ...