A/C Compressor Activation DDE 4.0

The A/C compressor is switched on and off by the DDE control unit (S_KOREL signal) via a relay. Switch-on of the A/C compressor is inhibited under following conditions:

• Start-off status:
  Road speed < 10 km/h AND
  Accelerator pedal > 30 % AND
  Engine speed < 1800 rpm
  
• Acceleration:
  Accelerator pedal change > 400 %/second AND
  Engine speed < 3000 rpm
  
• Coolant temperature > 117 °C
  
• Throttle dip:
  Engine speed < 755 rpm
  
• Start procedure
  
• Fault code stored in DDE:
  Fault code 1D "road speed signal" OR
  Fault code 25 "pedal position sensor"
  

Troubleshooting

The relay and relay activation are monitored but not the compressor itself. Fault code 74 "A/C compressor relay" is stored in the case of defect.