Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The A/C Pressure Transducer signal is a direct input to the Totally Integrated Power Module (TIPM). The Powertrain Control Module (PCM) receives the A/C pressure signal from the TIPM over the CAN C bus circuit.