Sunfire L4-138 2.3L DOHC VIN D MFI (1995)
Refrigerant Pressure Sensor / Switch: Description and Operation
PURPOSE
The Air Conditioning (A/C) refrigerant pressure sensor provides a signal to the Powertrain Control Module (PCM) which indicates varying high
side refrigerant pressure between approximately 0 kPa (0 psi) and 3102 kPa (450 psi).
OPERATION
The PCM uses this input to determine A/C compressor load on the engine to help control idle speed with Idle Air Control (IAC) valve.
The A/C refrigerant pressure sensor electrical circuit consists of a 5 volt reference line, a ground line, and a signal line to the PCM. The signal is a
voltage that varies from approximately 0.1 volt at 0 kPa (0 psi), to 4.9 volts at 3102 kPa (450 psi) or more.
A problem in the A/C refrigerant pressure circuits or sensor should set a Diagnostic Trouble Code P0530 A/C Refrigerant Pressure Sensor
Circuit and will make the A/C compressor clutch inoperative. See: Powertrain Management/Computers and Control Systems/Testing and
Inspection
