A4 V6-3.0L (AVK) (2004)
Terminal 3: B+ (terminal 75)
NOTE:
-
With harness connector -B- disconnected, the compressor will not engage.
-
The high pressure sensor -A- is an electronic control module, which creates a square wave signal, the duty cycle ratio changes with pressure in the
refrigerant circuit.
Pressure signal from High Pressure Sensor -G65-
A -
Refrigerant system pressure, high pressure side" in bar (absolute pressure)
B -
Signal ratio of square wave signal
C -
Characteristic curve
NOTE:
-
The A/C control head -E87- switches the compressor on as soon as no compressor cut-off condition exists (by activating the A/C Compressor
Regulator Valve -N280-):
-
If the duty cycle is greater than 12% (absolute pressure corresponds approx.; 1.8 bar), if smaller than 87.5% (pressure corresponds to approx.:
32 bar).
-
The compressor is not switched on if the duty cycle is smaller than 12 % or greater than 87.5 % (A/C Compressor Regulator Valve -N280- is
not activated).
-
The duty cycle and the calculated pressure by A/C Control Head -E87- is displayed in the measuring value block (display group 001). See:
Testing and Inspection/Scan Tool Testing and Procedures/Measuring Value Blocks (Function 08)
-
At absolute pressure, 0 bar corresponds to absolute vacuum. Normal ambient pressure corresponds to approximately 1 bar absolute pressure. 0
pressure corresponds to an absolute pressure of one bar on most pressure gauges (indicated by -1 below 0).
-
The A/C Control Head -E87- sends the request to switch on the coolant fans to the Engine Control Module (ECM) via the CAN-bus comfort
system, the ECM switches via the coolant fan control module the coolant fans on.
-
Independent from pressure in refrigerant circuit as soon as compressor is switched on.