High Pressure Sensor / Switch: Service and Repair
High Pressure Sensor (G65)
Special tools, testers and auxiliary items required
• Assembly Tool (T10118)
• Cooling performance cannot be checked with high pressure sensor removed, Climatronic control module (J255) does not switch on the A/C compressor.
• The refrigerant circuit remains closed, connection with valve.
• Checking function of high pressure sensor and signal sent. Refer to=> [ High Pressure Sensor (G65) Signal ] Description and Operation.
• The following describes removal and installation on a vehicle with a 2.0L TFSI engine and with a 3.2L MPI engine. On vehicles with another 4 or 6 cylinder engine, the procedure may differ.
• After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.
• Depending on the version of the high pressure sensor, an insufficient measuring value for the pressure in the refrigerant system will be sent by the high pressure sensor at low outside temperatures (lower than 5 °C) (even though the A/C system is OK and the refrigerant circuit is properly filled). At lower outside temperatures (ambient temperature lower than 5 °C), the Climatronic control module (J255) with part number "8J0 820 043" through to index "AJ"-might therefore make an incorrect DTC memory entry (DTC memory entry: high pressure sensor, and fall below the lower threshold). If the fault is displayed as a sporadic fault at an outside temperature greater than 5 °C, calculated by the A/C system, and if the A/C function is OK, then clear the DTC memory (no additional steps are necessary). This error does not occur with the Climatronic control module, part number "8J0 820 043" beginning with index "AK".
Removing
The high pressure sensor is at the right below the condenser.
• Depending on the version, it is installed directly on the condenser or on the refrigerant line.
- Remove the ribbed belt from generator. Refer to (only on 4 cylinder vehicles).
The coolant fan (V7) can come on when the engine is warm and cause serious personal injury.
- Disconnect electrical connector - A -.
- Remove the high pressure sensor (G65) - B - from the connection on the condenser on the refrigerant line.
Installing
• High Pressure Sensor (G65) tightening torque: 8 Nm.
Installation is done is reverse order, observe the following:
- Replace O-ring seal - C -. Refer to => [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-rings. Allocation, refer to Electronic Parts Catalog.
- Tighten high pressure sensor.
- Mount the ribbed belt on the belt pulley. Refer to (4 cylinder vehicles only).