A/C Pressure/Temperature Sensor G395
The A/C Pressure/temperature Sensor G395 is installed instead of the High Pressure Sensor G65.
Externally, the A/C Pressure/temperature Sensor G395 ( "grey" housing at present) and the High Pressure Sensor G65 ( "black" housing at present) currently only differ in terms of housing color and attention is therefore to be paid to correct assignment on replacement (part number → Electronic Parts Catalog ETKA ). As these two sensors emit different signals, the relevant control module can only evaluate the signal to which it has been matched.
When voltage is applied, the A/C Pressure/temperature Sensor G395 exchanges information via the air conditioner data bus system ( "LIN bus" ) with the corresponding control module. The relevant control module uses this information to calculate the pressure and temperature in the refrigerant circuit and any faults detected are signalled to the control module.
The temperature measured by the A/C Pressure/temperature Sensor G395 differs on account of the design of the A/C Pressure/temperature Sensor G395 and the component location from the actual temperature of the refrigerant in the refrigerant circuit. It is therefore not evaluated at present by all control modules and used for air conditioner control.
This information is used for example by the control head, Climatronic Control Module J255 to calculate the pressure in the refrigerant circuit and to actuate the downstream control modules (coolant fan control module, Engine Control Module (ECM) etc.) by way of the data bus system. These control modules then regulate, for example, the coolant fans and engine accordingly → 87 - Air conditioning .