Dimmable Backlighting

When the parking lamps are on, the SJB monitors the input from the instrument panel dimmer switch.

Based on input from the instrument panel dimmer switch, the SJB sends a pulse-width modulated voltage to the dimmable switches.

The SJB sends a message over the Controller Area Network (CAN) to the Front Controls Interface Module (FCIM), the Audio Control Module (ACM) and the Instrument Panel Cluster (IPC) to indicate the backlighting intensity level. If the receiving module receives invalid backlighting data from the SJB 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 SJB or if the data received is deemed invalid for more than 5 seconds, the receiving module sets a missing message related DTC in continuous memory and defaults the backlighting to full nighttime intensity.