A/C-compressor activation, S54

A/C-compressor activation, S54 engine

The A/C compressor is controlled as follows:

• Operation of the air conditioning button
  

• Passing on the request via the instrument cluster to the engine management system
  

• Setting the operating state ”Air conditioning system on” by the engine management system if sufficient resources are available
  

• Passing on the status of the engine management system to the instrument cluster via the K bus
  

• Passing on the request from the instrument cluster via the K bus to the air conditioning system control unit
  

• The air-conditioning compressor is activated via the hard-wired cable S_KOREL between the heater/air conditioning system and the engine management system (see connection scheme).
  

Diagnosis

The diagnosis of the A/C-compressor activation consists of electrical monitoring of the activation line. In the event of faults, only fault 2F12 is stored.

This means that in the event of a fault the entire signal path must be checked. Here, it makes sense also to use the diagnosis in the integrated automatic heating and air conditioning system.