Manual Windows; Power Windows - GMC Chevrolet Silverado 2500HD 2021 Owner's Manual

38 Keys, Doors, and Windows
The vehicle aerodynamics are designed to
improve fuel economy performance. This
may result in a pulsing sound when either
rear window is down and the front windows
are up. To reduce the sound, open either a
front window or the sunroof, if equipped.

Manual Windows

If equipped, turn the hand crank on each
door to manually raise or lower the manual
windows.

Power Windows

Warning
Children could be seriously injured or
killed if caught in the path of a closing
window. Never leave the Remote Keyless
Entry (RKE) transmitter or keys in a
vehicle with children. When there are
children in the rear seat, use the
window lockout button to prevent
operation of the windows. See Keys (Key
Access) 0 7 or
Keys (Keyless Access) 0 9.
The power windows work when the ignition
is on, in ACC/ACCESSORY, or when Retained
Accessory Power (RAP) is active. See
Retained Accessory Power (RAP) 0 229.
Using the window switch, press to open or
pull to close the window.
The windows may be temporarily disabled if
they are used repeatedly within a
short time.
Window Lockout
With Power Folding Mirrors, Without Similar
This feature stops the rear door passenger
window switches from working except from
the driver position.