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Home >> Audi >> 1994 >> 100CS Quattro Sedan V6-2.8L (AAH) >> Repair and Diagnosis >> Heating and Air Conditioning >> Refrigerant Pressure Sensor / Switch >> Low Pressure Sensor / Switch >> Service and Repair
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Low Pressure Sensor / Switch: Service and Repair

Function
Switches A/C clutch -N25- OFF if system suction pressure is too low (low refrigerant charge). This switch protects the compressor if the refrigerant system is empty.
- Switch located in right plenum.
- Switch opens (compressor OFF): 1.45 - 1.6 bar (21 - 23 psi).
- Switch closes (compressor ON): 2.9 - 3.4 bar (42 - 49 psi).

Removing And Installing
- Remove plenum tray.
- Remove electrical connector and unscrew low pressure switch -F73-. Refrigerant system remains closed (Schrader valve under switch).





- Install new O-ring -A- (8.9 mm x 1.8 mm), lubricate with refrigerant (PAG) oil and ensure proper seating in groove.
- Torque switch to 5 Nm (44 in lb).
- Install plenum tray.
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