See also:

Manual Operation of Power Liftgate
To change the liftgate to manual operation, press OFF on the power liftgate switch. A message displays on the DIC indicating manual operation mode. See Driver Information Center (DIC) (Without DIC B ...

Instantaneous Economy and Active Fuel Management™ Indicator
If the vehicle has this display, press the trip/fuel button until INST ECON V8 displays. This display shows the current fuel economy at a particular moment and will change frequently as driving condit ...

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 ...