Normal Operation
The HVAC module communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits (GY/O) (MS-CAN +) and (VT/O) (MS-CAN -) provide the network connection to the HVAC module. The HVAC module shares the MS-CAN with the instrument cluster (IC), smart junction box (SJB), audio control module (ACM), satellite digital audio receiver system (SDARS) module, front control interface module (FCIM) and front display interface module (FDIM). Voltage to the HVAC module is provided by circuit (W/R) and circuit (W). Ground is provided by circuit (B/L).