TT Quattro Coupe V6-3.2L (BHE) (2005)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/C Pressure Switch -F129-, Switch Functions
The high/low pressure switch (located between terminals -1- and -2-) disengages A/C clutch -N25- (via A/C control head -E87-) when there are
excessively high or low refrigerant system pressures.
Switching pressures (in bar)
Switch open (A/C clutch -N25- off):
-
Low pressure: switch opens at 1.2 bar and closes at 2.4 bar
-
High pressure: switch opens at 32 bar and closes at 24 bar
Switch closed (compressor on):
-
1.2 (2.4) bar to 32 (24) bar
The high pressure switch (between terminals -3- and -4-) switches coolant fan(s) -V7- to speed 2.
Switching pressures (in bar):
-
Fan speed 2 on (switch closes) at 16 bar
-
Fan speed 2 off (switch opens) at 12.5 bar
Removing and installing
-
Disconnect harness connector.
-
Remove A/C pressure switch -B-.
Tightening torque: 5 Nm (44 in. lb)
-
Replace O-ring seal -A- (10.8 mm x 1.8 mm).