Networked Illumination Operation

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

The networked switches and components are illuminated when the headlamp switch is in the PARK, ON, or AUTO position. The system-wide illumination dimming level is determined by the BCM based on inputs from the ambient light sensor and the dimmer switch (integral to the headlamp switch).

The BCM sends the dimming level message to the GWM on the HS-CAN1. The GWM sends the signals to their intended receiving modules on the MS-CAN and the HS-CAN3 as follows:

MS-CAN

DDM
PDM
FCIM

HS-CAN3

IPC
ACM
APIM
FCDIM

The receiving modules use the illumination dimming level message to determine the backlighting intensity of networked and non-networked illumination sources. If a module does not receive the illumination dimming level message or the data received is deemed invalid, the module sets a CMDTC in the respective module and the illumination defaults to full intensity.

If the IPC does not receive the dimming level or ambient light level network messages from the BCM for up to 5 seconds, the IPC illumination intensity remains at the level commanded by the last dimming level message received from the BCM. If the IPC receives invalid or no signals for more than 5 seconds, the IPC sets a DTC and defaults to full intensity.

When the exterior lamps are activated during the daytime, the message center illumination remains at full intensity and does not dim due to the day/night status message received from the light sensor. When the vehicle travels through an area where ambient light is decreased, the illumination intensity of the message center decreases. The message center illumination resumes full intensity when increased ambient light is detected.