A/C Signal: Description and Operation

A/C Pressure Sensor:

A/C PRESSURE SENSOR

The A/C pressure sensor, which is of a new type delivering a linear signal, supplies the ECM with information regarding the pressure in the A/C high pressure circuit.

The purpose is to control the following functions:
^ Starting of the engine cooling fan at low speed
^ Starting of the engine cooling fan at high speed
^ Switch-out of the A/C compressor if the system pressure becomes excessive
^ Idling compensation for A/C load (only normally aspirated engine)

The sensor is supplied at 5 Volts by the ECM. The sensor signal may vary from 0 to 5 Volts, depending on the system pressure. Low pressure produces a low- voltage signal and high pressure a high-voltage signal.

The sensor is installed in the A/C high-pressure circuit.