CTS V8-5.7L VIN P (2004)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/C REFRIGERANT PRESSURE SENSOR
The A/C refrigerant pressure sensor is a 3-wire piezoelectric pressure transducer. A 5-volt reference, low reference, and signal circuits enable the sensor
to operate. The A/C pressure signal can be between 0-5 volts. When the A/C refrigerant pressure is low, the signal value is near 0 volts. When the A/C
refrigerant pressure is high, the signal value is near 5 volts.
The A/C refrigerant pressure sensor prevents the A/C system from operating when an excessively high or low pressure condition exists. If the ECM
detects a failure in the A/C refrigerant pressure sensor or circuit, the class 2 message sent to the HVAC control module will be invalid. The HVAC
control module will then send a request to the Radio for display of the SERVICE A/C SYSTEM that will be displayed on the DIC. The HVAC control
module will also display A/C OFF on the module as long as the condition is present.