Refrigerant Temperature Sensor (G454)

Refrigerant Temperature Sensor (G454)

Removing

• The connection for refrigerant temperature sensor is not equipped with valve

• Refrigerant must be extracted from refrigerant circuit before removing refrigerant temperature sensor. If refrigerant temperature sensor is not removed within 10 minutes after extraction, pressure may build up in refrigerant circuit by renewed evaporation. Extract refrigerant once more.

• The refrigerant temperature sensor was discontinued as of November 2007 as a running change. On vehicles with the Comfort A/C system, make sure the Climatronic control module (J255) for the Comfort A/C system is installed. Vehicles with a 6 cylinder TDI engine or an 8 cylinder engine but without a refrigerant temperature sensor may only have the Comfort front control and display unit installed (part number 4L0 820 043, beginning with index letter K). Refer to the Electronic Parts Catalog and Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding".

• If the vehicle has the Basis A/C system without a refrigerant temperature sensor, and the sensor is being displayed as a fault, then perform an adaptation to the Basis front A/C control head. It is not necessary to perform this on the Comfort A/C system because it has different versions of the front A/C control head. On vehicles wit the Basis A/C system, Guided Fault Finding displays the fault missing refrigerant temperature sensor and the evaluating of the refrigerant temperature sensor switches off (by entering adaptation) using Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding".

• The refrigerant temperature sensor- 2 - is inside the refrigerant line in front of the engine on vehicles with an 8 cylinder TDI engine.






- Discharge the refrigerant circuit.

- Remove the noise insulation.

- Disconnect connector - A -.






- Check pressure in refrigerant circuit for example, using a pressure gauge from an A/C service station.

Only remove refrigerant temperature sensor when pressure in refrigerant circuit is the same or less than the ambient pressure.

- Using an open-end wrench, counter-hold refrigerant line at hex head - D - and remove refrigerant temperature sensor - B - from refrigerant line of A/C compressor.

Installing

• Position the wrench only on the hex when tightening the refrigerant temperature sensor.

Installation is carried out in the reverse order while noting the following:

- Install the O-ring - C -. Refer to the Electronic Parts Catalog.

- Coat O-ring seal - C - lightly with refrigerant oil before installing, refer to => [ Refrigerant Circuit O-Rings ] Refrigerant Circuit O-Rings.

- When installing, make sure that O-ring seal - C - is positioned correctly in groove of refrigerant temperature sensor - B -.

- Using an open-end wrench, counter-hold refrigerant line at hex head - D - and tighten refrigerant temperature sensor - B - to 8 Nm.