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 ...

Gasoline Octane
Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you may notice an audible knocking noise when you drive, commonly referred to as sp ...

Using the Call Command
1. Press and hold for two seconds. The system responds with “Ready” followed by a tone. 2. Say “Call”. The system responds with “Call using <phone name>. Please say the name ta ...