See also:

Window Lockout
(Window Lockout): If a crew cab or extended cab vehicle has power windows, the driver door power window switch has a lockout feature. This feature prevents the rear windows from operating, except fr ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment on page 9‑64. Added electrical equipment ...

Unable to Connect to OnStar Message
If there is limited cellular coverage or the cellular network has reached maximum capacity, this message may come on. Push to try the call again or try again after driving a few miles into another ce ...