Description And Operation: Operation

The A/C compressor can be activated through customer interface, humidity sensor conditions, or recirculation door position. When the HVAC module receives a request to activate/deactivate the compressor, the HVAC module sends a request to the Powertrain Control Module (PCM) to activate the clutch via Controller Area Network (CAN) bus signals. The PCM activates/deactivates the A/C Clutch upon receiving the request. The HVAC sends an internal signal to the A/C Compressor solenoid to change the compressor displacement (stroke). Once the AC Switch-ON Conditions are fulfilled, the clutch status will be transmitted by the PCM on the CAN bus to the HVAC module. Once the compressor is activated, the HVAC module will control the variable compressor volume via an internal Pulse Width Modulated (PWM) signal, control evaporator temperature and transmit the PWM output current value to the PCM on the CAN bus.