See also:

Overheated Engine Protection Operating Mode
If an overheated engine condition exists and the message ENGINE OVERHEATED STOP ENGINE is displayed, an overheat protection mode which alternates firing groups of cylinders helps prevent engine ...

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 ...

Automatic Headlamp System
When it is dark enough outside, the Automatic Headlamp System turns on the headlamps when the vehicle is started and after the transaxle has been shifted out of the PARK (P) position. The headla ...