Instrument Panel and Interior Switches Illumination - System Operation and Component Description

Non-Networked Illumination Operation

Based on the ambient light level input from the light sensor and the requested illumination dimming level input from the dimmer switch, the BCM calculates the correct dimming level for the non-networked illumination sources. The BCM provides a pulse-width modulated voltage to all non-networked illumination sources.

The start/stop switch is non-networked to the BCM but integral to the FCIM and cannot be serviced separately.

Non-dimmable illumination is supplied to the window control switches with the ignition switch ON or OFF, when the accessory relay is energized.

Field-Effect Transistor (FET) Protection

Field-Effect Transistor (FET) protection is used to protect the BCM output drivers from damage in the event that an excessive current draw is detected on a BCM output. Each illumination circuit connected to the BCM is separately protected. Refer to the System Diagram in this section to view the different groups of BCM non-networked illumination outputs. For a full description of Field-Effect Transistor (FET) protection, Refer to: Module Controlled Functions - System Operation and Component Description (419-10 Multifunction Electronic Modules, Description and Operation).

Component Description

Dimmer Switch