Porsche P-80 2005, Manual

Page: 70 / 108

Page 4.12
Climate Control Systems Diagnosis & Repair
Cayenne Model System
Climate Control Unit
The Climate Control Unit contains an electronic processor
which receives inputs from sensors and provides outputs
to control actuators. Sensor information includes outlet air
temperature and passenger compartment air temperature.
The passenger compartment air temperature value is
compared with the passenger-selected value. If the two
values are different, the Climate Control Unit commands
electric servo motors to move air distribution flaps to
change the outlet air temperature. The Climate Control
Unit is located in the dash and has the manual passenger’s
controls.
The standard Cayenne automatic climate control system
provides 2-zone control, while a 4-zone with front and rear
control is optional.
2-Zone
Both temperature and air volume can be independently set
left and right. The system will maintain the set temperature
as conditions change.
Depressing the “Auto” button switches the system to
automatic operation. When ambient temperatures are
< 2° C (36° F), the processor does not permit A/C
compressor operation, even when the Auto button is
depressed.
After the vehicle is turned off, depressing the “Rest”
button allows continued heating of the interior for up to 20
minutes. This function circulates hot coolant and operates
the blower.
2-Zone Sensors & Actuators