Refrigerant Pressure Sensor / Switch: Service and Repair

Function:
High pressure switch -F23- (contacts -1 - and -2- in switch -A-) switches coolant fan V7 into stage 2 (contacts -1- and -2- in connector -B-) when A/C system pressure increases.

Switching pressures:
- Fan stage 2 on (switch closes): 14.3 to 17.3 bar pressure
- Fan stage 2 off (switch opens): 10.9 to 15.3 bar pressure
- Pressure difference between switching points: 2.0 to 3.4 bar

High-pressure switch F118 (contacts -3- and -4- in switch -A-) switches the compressor off via A/C control head E87 (contacts -3- and -4- in connector -B-) if excess pressure exists in refrigerant system.

Switching pressures:
- Compressor off (switch opens): 28.2 to 31.0 bar pressure
- Compressor on (switch closes): 11.5 to 15.0 bar pressure

Removing and installing
- Remove front bumper.







- Disconnect electrical harness connector.
- Replace O-ring seal -A-, 7.6 mm; 1.8 mm.
- Tightening torque: 5 Nm (44 in lb)


NOTE:
- To test refrigeration system pressures with switch -B- removed, bridge vehicle wiring harness connector.
- The refrigerant system remains closed due to the Schrader valve.