Refrigerant Pressure Sensor / Switch: Description and Operation

GF83.40-P-2193RI Refrigerant Pressure Sensor, Component Description
'

Component Identification:

Location
The refrigerant pressure sensor is located in the front left of the engine compartment at the fluid reservoir (1).

Task
The refrigerant pressure sensor registers the refrigerant pressure. The value is read in by the driver-side SAM control unit (N10/10) and transmitted to the AAC [KLA] control and operating unit (N22) via the interior CAN.The refrigerant pressure sensor operates in a pressure value range of p = 0 to 35 bar.
The engine and air conditioning electric suction fan with integrated control (M4/7) is actuated depending on the read-in refrigerant pressure and a characteristic stored in the control and operating unit. If the refrigerant pressure increases to more than p = 26 bar, the refrigerant compressor (A9) is linearly controlled back to the shut-off limit.

The refrigerant compressor is shut off with:
- Refrigerant pressure < 1.75 bar
- Refrigerant pressure > 30 bar

The refrigerant compressor is switched on with:
- Refrigerant pressure > 2,25 bar
- Refrigerant pressure < 26 bar

In order to prevent refrigerant underfilling, the registered pressure values are compared with the minimum pressure values stored in the control and operating unit and used to calculate the refrigerant level. At the same time, AC mode is deactivated and cannot be reactivated.
The system is not functional again until the relevant fault has been remedied and the fault memory in the control and operating unit has been deleted.