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 ...

Automatic Transmission Fluid
It is not necessary to check the transmission fluid level. A transmission fluid leak is the only reason for fluid loss. If a leak occurs, take the vehicle to the dealer and have it repaired as soon a ...

Navigation
OnStar navigation requires the Directions and Connections service plan. Push to receive directions or have them sent to the vehicle navigation screen. Destinations can also be forwarded to the vehic ...