2007 GMC Sierra 1500 Pickup Owner's Manual - Page 186

Outside Power Foldaway Mirrors If your vehicle is equipped with this feature, the controls are located on the driver's door armrest. To fold or unfold the mirrors, move the selector switch, located above the mirror control, to the middle position. The mirror control will illuminate. Press the right or left side of the mirror control to fold or unfold the mirrors. You may notice the mirror glass adjust as the mirrors fold in; this is normal. The mirror glass will reposition itself once the mirrors are unfolded. If the mirrors are accidentally folded/unfolded manually, they may shake or flutter at normal driving speeds and may not stay in the unfolded position. If this happens, you will need to reset the mirrors. See "Resetting the Power Foldaway Mirrors" next. Move the upper selector switch to the left or right to choose the mirror you want to adjust; then press the dots located on the four-way control pad to adjust the mirror. The mirrors may also include a memory function which works together with the memory seats. See Memory Seat and Mirrors on page 12 for more information. 186