Refrigerant Circuit

Refrigerant Circuit (2-Zone and 4-Zone System)







With the electronically controlled compressor and condenser with integrated mounting for the dryer equipment (dryer cartridge), the refrigerant circuit is similar to that in the Cayenne. The electronic control valve in the compressor is actuated by the OAU. The OAU uses the evaporator temperature sensor value as the main input variable for the actuation. When outside temperatures are less than 27 °F. (-3 °C.) or the intake air temperature is less than 36 °F. (2 °C.), the compressor is always switched off automatically.

Compressor Switch-off Conditions Codes

The compressor's OFF code uses the PIWIS Tester to assign the reason for switching off. If the charging condition of the battery is critical, the following air-conditioning functions are restricted initially and then switched off:
- Heated seats
- Heated rear window/door mirror heating
- Fresh air fan
- Air-conditioning compressor

Codes
0 - OK (no switch-off condition)
1 - High-pressure cut-off
2 - Low fan speed
3 - Low-pressure cut-off
4 - ECON
5 - Engine start
6 - ECON mode
7 - AC off (fan OFF)
8 - Outside temperature
9 - Not used
10 - Low battery voltage
11 - High engine temperature
12 - Engine control module (engine temperature is too high)
13 - High battery voltage
14 - Evaporator temperature sensor (risk of freezing)
15 - Three overpressure events
16 - Servo motor fault (e.g. servo motor)
17 - Pressure sensor fault
18 - Overheating protection (if engine speed is too high)
19 - Vehicle electrical system control unit requirement
20 - Low refrigerant level
21 - Compressor run-in period (end of assembly line)
22 - Run-in period is not yet completed

NOTE:
- Since the compressor system is similar to that in the Cayenne, the OFF code can also be used for diagnosis purposes.
- Code 8: When outside temperatures are less than 27 °F. (-3 °C.) or the intake air temperature is less than 36 °F. (2 °C.), the compressor is always switched off automatically
- Code 12: Switch-off request from the DME control unit (e.g. when T_Mot greater than 244 °F. (118 °C.)
- Code 19: Switch-off request from battery control unit or vehicle electrical system control unit
- Code 21: During the run-in period, the compressor is switched off if the engine speed of greater than 1200 rpm is exceeded