A/C Compressor Activation

Function

The A/C compressor is controlled as follows:

• Operation of the air conditioning button
  

• Forwarding the request via the central gateway (junction box, instrument cluster or SGM) to the DME/DDE
  

• Setting of the operating mode ”Air conditioning on” by the DME/DDE
  

• Transfer of the request from the DME/DDE via powertrain CAN to the gateway (junction box, instrument cluster or SGM)
  

• Forwarding of the request from the central gateway via K-CAN to the electrical control valve on the air conditioning compressor
  

• Activation of the air conditioning compressor
  

The A/C compressor is switched off in precisely the same way.

This procedure ensures that at the time the air conditioning compressor is switched on, the engine has sufficient power reserves. Activation of the A/C compressor does not bring about a dip in engine speed.

Diagnosis

In the event of a fault, the entire signal path must be checked.