Mercedes-Benz C-Class 2014 Owner's Manual page 173

Operating the climate control system
170
To activate pre-entry climate control:
X
unlock the vehicle with the key or KEYLESS-
GO.
The air-conditioning functions are activated
for up to 120 seconds for preheating and
for up to 60 seconds for pre-cooling.
The pre-entry climate control switches off
automatically when the engine is started.
Seat heating (heating), seat ventilation (ven-
tilation), perfume atomiser and ionisation
remain switched on after starting the engine.