Circuit/System Description

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Accent Lamps

With the headlamp switch in the PARK or HEAD position, the park lamp switch signal circuit provides an input to the body control module (BCM). The BCM responds by applying voltage to the backlight dimming control circuits illuminating all components with interior backlighting. All interior backlighting turns ON at the dimming level indicated by the Dimmer Switch. The instrument panel Dimmer Switch is a variable resistance rotary type switch. A voltage signal is sent to the switch and the switch is grounded via a low reference circuit to the BCM. The signal will vary with resistance (switch position) and the BCM will measure the value through the switch signal circuit. The BCM interprets the signal and applies a pulse width modulated voltage through the backlighting control circuits illuminating the interior backlighting to the requested level of brightness. The BCM simultaneously sends a serial data message to the Instrument Panel Cluster Control Module, Info Display Module, Transmission Range Selector Controls, Heater and Air conditioning User Interface Control, Front Overhead Console Assembly, Read Audio Control Module, and the Radio.