Refrigerant Pressure Sensor / Switch: Description and Operation

An electronic A/C pressure sensor is mounted in the line (between the compressor and the condenser). Its output to the PCM is variable and is dependent upon pressure inside the line. A higher pressure results in a higher voltage output. The PCM constantly monitors A/C system pressure to:

1. Disengage the A/C clutch if the pressures are too high.
2. Disengage the A/C clutch if pressures are too low.
3. Boost idle air control to compensate for A/C load at idle.
4. Control cooling fan operation.

The pressure sensor is not repairable, if it fails, it must be replaced.