Discharge Air Temperature Sensor / Switch: Service and Repair

A/C Pressure/Temperature Sensor (G395)

• The cooling output cannot be checked when the A/C pressure/temperature sensor is removed. The Climatronic control module (J255) display and control head does not switch on the A/C compressor.

• The refrigerant circuit remains closed, connection with valve.

• Only A/C pressure/temperature sensor (G395) may be installed on this vehicle (the LIN bus performs the data exchange). Refer to the Parts Catalog.

• A high pressure sensor (G65) cannot be installed on this vehicle (it only delivers square-wave signals). Refer to Electronic Parts Catalog (ETKA).

Removing

- Turn off the ignition.

- Remove the upper cover on the lock carrier cover.

- Disconnect the electrical connector - A -.






- Disconnect the A/C pressure/temperature sensor - A - from the condenser connector - C -.






Installing

Installation is done is reverse order, observe the following:

- Replace the O-ring - B -. Refer to => [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-Rings. Refer to the Parts Catalog.

- Tighten the A/C Pressure/Temperature Sensor - A -.

• Tightening specification: 5 Nm.

- Check the Climatronic control module (J255) display and control head DTC memory and erase any displayed malfunctions if necessary. Refer to the Vehicle Diagnostic Tester under "Guided Fault Finding".

Checking the A/C pressure/temperature sensor signal, refer to => [ A/C Pressure/Temperature Sensor (G395), Checking Pressure Signal ] A/C Pressure/Temperature Sensor (G395), Checking Pressure Signal.

• The signal from the A/C pressure/temperature sensor is checked as described in Guided Fault Finding for the A/C system. Refer to the Vehicle Diagnostic Tester under "Guided Fault Finding".

• The vehicle electrical system control module (J519) evaluates the A/C pressure/temperature sensor signal. It is transmitted via the Data bus to the Climatronic control module (J255).

• If a malfunction in the signal from the A/C pressure/temperature sensor is recognized, then the malfunction will be entered in the vehicle electrical system control module memory and in the Climatronic control module. It will be necessary to the check the vehicle electrical system control module DTC memory when reading the Climatronic control module DTC memory. Refer to the Vehicle Diagnostic Tester under "Guided Fault Finding".

• The A/C pressure/temperature sensor measured values are displayed in the vehicle electrical system control module measured values block using the Vehicle Diagnostic Tester under "Guided Fault Finding". The displayed temperature is currently not used by the Climatronic control module.