Regulation of Automatic air conditioning, function - GF83.40-P-2004MCU

MODEL 451.3/4 with CODE (I01) Air conditioning Plus 

Fig 1: Regulation Of Automatic Air Conditioning Function Diagram

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function 

The automatic air conditioning is regulated via the heater/AC operating unit, which is networked with the vehicle electronics via CAN. This permits the best possible climate control while considering any climate-relevant events, as well as the adaptation of the engine management to the power absorption capacity of the refrigerant compressor.

The following information is directly read in by the heater/AC operating unit: 

• Evaporator temperature via evaporator temperature sensor
• Refrigerant pressure via refrigerant pressure sensor
• Interior temperature via the interior temperature sensor (N23b1) integrated in the heater/AC operating unit
• Position feedback by the blend air flap actuator

The following information is transmitted to the heater/AC operating unit via CAN: 

• Outside temperature via the instrument cluster
• Coolant temperature via the ME control unit

The following components are directly actuated by the heater/ AC operating unit: 

• Blend air flap actuator
• Air recirculation flap actuator motor

The following components are actuated by the heater/AC operating unit via CAN: 

• Refrigerant compressor via SAM control unit

  To prevent damage to the climate control system, the refrigerant compressor is switched off at refrigerant pressures above 28 bar.