Dimmable Backlighting

The dimmable switches and components are illuminated when the headlamps and parking lamps are on or off. The illumination dimmer switch controls all dimmable interior illuminated components.

Based on the ambient light level and illumination dimmer position messages received from the BCM, the IPC calculates the correct dimming level. The IPC then sends the illumination dimming level message to the BCM, HVAC module, DDM, PDM and the Image Processing Module - B (IPM-B) on the Medium Speed Controller Area Network (MS-CAN) and to the APIM and FCIM on the Infotainment Controller Area Network (I-CAN).

The receiving modules use the illumination dimming level message to determine the backlighting intensity of integral illumination sources. The BCM sends a pulse-width modulated voltage to hardwired dimmable components on 3 circuits based on the illumination dimming level message from the IPC. 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 night time intensity.