w140 Climate control???
 

I have read many threads regarding climate control but still i did not understand fully the main purpose of this rest function when do we need it and why and will the ac well perform better in air flow and colder air i mean if i disconnect the battery will it reset hole system?

Is this a USA market car if not where rest is to provide heat into cabin when engine is off electric water pump runs to circulate through heater core fan runs on low