Dimmable Backlighting

The instrument panel dimmer switch is integral to the Front Lighting Control Module (FLM). When the parking lamps are on, the FLM  sends an illumination command message to the Body Control Module (BCM) over the High Speed Controller Area Network (HS-CAN). The BCM  sends voltage to the hardwired dimmable components and switches based on the network message received from the FLM  .

The BCM  also sends a message over the Controller Area Network (CAN) to the Instrument Panel Cluster (IPC), the FLM  and the HVAC module, to indicate the backlighting intensity level. The IPC  gateways the message from the HS-CAN  to the Infotainment Controller Area Network (ICAN) to the Front Controls Interface Module (FCIM), the Front Control/Display Interface Module (FCDIM) (if equipped), and the Accessory Protocol Interface Module (APIM) (if equipped). If equipped, the Front Display Interface Module (FDIM) is attached to the APIM  . The APIM  gateways the illumination intensity level message to the FDIM  . A bar graph window is displayed in the message center of the IPC  indicating the backlighting intensity level.

If the receiving module receives invalid backlighting data from the BCM  for 5 seconds or less, the receiving module defaults the backlighting to the last setting.

If the receiving module does not receive the backlighting status message from the BCM  or if the data received is deemed invalid for more than 5 seconds, the receiving module sets a DTC in continuous memory and defaults the backlighting to full nighttime intensity.