Theory Of Operation
The rear passive entry sliding door handle switches are hard wired to and monitored by the Left Rear Door Module (DMRL). The status of the sliding door handle switches are sent as a CAN-IHS bus message by the DMRL; through the Body Control Module (BCM) to the Radio Frequency Hub Module (RFHM). The RFHM is connected to a fused B(+) circuit and has a path to ground at all times. These connections allow it to remain functional regardless of the ignition switch status. Any input to the RF Hub that controls a vehicle system function that does not require that the ignition switch status be ON such as depressing a button on an Remote Keyless Entry (RKE) or Frequency Operated Button with Integrated Key (FOBIK) transmitter, prompts the RF Hub to wake up and transmit on the CAN-C bus. The RF Hub uses On-Board Diagnostics (OBD) to monitor all hard wired inputs, outputs, functions and conditions.