This walkthrough will introduce you to the steps of enabling the standby functions of the Wii U console. By enabling this feature you will also allow your console to perform background tasks when not in use (download system updates, add-ons,...).
NB: The Wii U console displays an orange LED when in standy mode.
To enable this feature:
Start your Wii U.
Tap the Settings button (denoted by a small wrench) of the Wii U gamepad.
The System Settings menu will be displayed.
Use the left stick of the Wii U gamepad, move to the Power Settings.
Select Configure Standby-Functions Setting.
Tap on Enable and follow the onscreen instructions.