Networked Illumination Operation

The system-wide illumination dimming level is determined by the BCM  . Based on the ambient light level input from the autolamp/sunload sensor and the requested illumination dimming level input from the dimmer switch, the BCM  calculates the correct dimming level. The BCM  sends the illumination dimming level message to the GWM  on High Speed Controller Area Network 1 (HS-CAN 1). The GWM  then distributes the message to the FCIM  , DDM  and PDM  on the Medium Speed Controller Area Network (MS-CAN) and the IPC  , ACM  , APIM  and FCDIM  on the High Speed Controller Area Network 3 (HS-CAN 3). The DDM and PDM  send the illumination dimming level data to the Driver Rear Door Module (DRDM) and Passenger Rear Door Module (PRDM) via LIN  circuits.

The receiving modules use the illumination dimming level message to determine the backlighting intensity of internal and external harwired illumination sources. If a module does not receive the illumination dimming level message or the data received is deemed invalid, the module sets a DTC  in continuous memory and defaults to full nighttime intensity.