FixVault

Auto button, location / task / function - GF83.40-P-2147GI

MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning 

Fig 1: Identifying Auto Button And Temperature Thumbwheel
G04608959AUTO BUTTONAUTO BUTTONCourtesy of MERCEDES-BENZ USA
  Auto button, location The auto button (AUTO BUTTON ) is located in the center in the upper half of the temperature selector wheel (2) on the AAC push-button control module (N22).  
  Auto button, purpose By pressing the auto button (AUTO BUTTON ) automatic switching is activated. Function feedback takes place by means of a red LED.  
  Auto button, function In addition to regulating the temperature, the blower speed and the air distribution are also regulated automatically in automatic mode. The blower speed is continuously controlled depending on the temperature difference between the specified and actual values.