Ok, so the sensor on the condenser is the actual A/C Fluid Pressure Sensor (High or Low Pressure).
A/C Fluid Pressure Safety
The status of the air conditioning high and low pressure safety is transmitted by the BSI via a linear pressure sensor.
The linear pressure sensor measures the pressure of the air conditioning fluid.
The reception of pressure information is carried out by the engine ECU through a wire link.
The engine ECU makes the following information available to the BSI on the CAN network:
- Air conditioning compressor cut-off due to safety function; Air conditioning compressor cut-off due to risk of overheating
- Coolant pressure; 0 to 3100 KPa
The BSI sends the information to the air conditioning ECU via the COMFORT VAN network.
High Pressure Safety
The high pressure cut-off threshold and the retriggering threshold depending also on engine speed, are:
Cut-off threshold > 27 bars (absolute)
Retriggering threshold < 20 bars (absolute) and < 5650 rpm engine speed
Low Pressure Safety
The low pressure cut-off threshold and the retriggering threshold depending also on engine speed, are:
Cut-off threshold less than or equal to 2.5 bars (absolute)
Re-triggering threshold greater than or equal to 3 bars (absolute) and engine speed < 6250 rpm