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 ...

When the Change Engine Oil Soon Message Displays
Change engine oil and filter. See Engine Oil. An Emission Control Service. When the Change Engine Oil Soon message displays, service is required for the vehicle as soon as possible, within the ne ...

What to Use
WARNING: Adding only plain water to the cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil before the proper coolant mixture will. The vehicle’s cool ...