Air Conditioning (A/C) Pressure Sensor
The air conditioning (A/C) pressure sensor detects the pressure in the high-pressure side of the air conditioning (A/C) system. This is so the engine control module (ECM) can control:
- engine cooling fan (FC) start
- stopping the compressor if the pressure in the air conditioning (A/C) is too high
- constant idle speed compensation for the air conditioning (A/C) compressor load.
The sensor is linear. It is grounded in the control module and supplied with a 5 Volt current from the control module. A linear signal (between 0-5 V depending on the pressure in the air conditioning (A/C)) is transmitted to the control module. At 0.25 kPa or lower, the voltage is 0 V, at 3100 kPa the voltage is approximately 4.75 V. Low pressure results in low voltage, high pressure in high voltage.
The engine control module (ECM) can diagnose the air conditioning (A/C) pressure sensor. The sensor value can be read off using VIDA (Volvo scan tool).
The air conditioning (A/C) pressure sensor is positioned on the high pressure delivery line for the air conditioning (A/C) system.