Mercedes-Benz SL SERIES Operator's Manual page 142

Operating the climate control systems
140
Activating or deactivating
Example: ¿ button
To activate: press the ¿ button.
X
The indicator lamp in the ¿ button lights
up.
To deactivate: press the ¿ button.
X
The indicator lamp in the ¿ button goes
out. The "Cooling with air dehumidification"
function has a delayed switch-off feature.