See also:

Setting the center air vents
Center air vent, left Center air vent, right Center vent thumbwheel, right Center vent thumbwheel, left To open/close: turn thumbwheels 3 and 4 up or down. ...

Vehicle data, GL 550
The data stated here refers specifically to a vehicle with standard equipment. Consult an authorized Mercedes-Benz Center for the data for all vehicle variants and trim levels. ...

Important notes
In order to prevent the vehicle's battery from discharging, the interior lighting functions are automatically deactivated after some time except for when the SmartKey is in position 2 in the i ...