A/C Pressure Sensor/Switch - Cooling Fan: Description and Operation

The A/C Pressure Fan Switch is a normally closed switch that monitors high side pressure during A/C operation. When high side pressure reaches 1448 kPa (210 ±psi) the switch opens signaling the Powertrain Control Module (PCM) to turn the primary cooling fan to high speed.

The switch closes once pressure drops to approximately 1103 kPa (160 psi).