The 2009 Chevrolet Tahoe's rear window is usually a power window. There should be a switch located on the driver's side door panel, within the master power window controls. This switch will typically have individual buttons for each window, including the rear window. Look for a button that shows a rear window graphic or is clearly labeled "Rear" or similar.
If it doesn't operate via the driver's side controls, there might also be a switch on the rear passenger door (less common in this model year). Check for a switch there as well.
If neither of those work, there might be a problem with the window motor, the switch itself, or a fuse. Check your owner's manual for details on fuse locations and troubleshooting.
