Interior Lamps Dimming

WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

The second group includes lamps which may be dimmed.

Door lock switch - driver
Door lock switch - passenger
Fuel economy mode switch
Hazard warning switch
Headlamp switch
HVAC control head assembly
Instrument cluster
Multifunction switch - center console
Multifunction switch - instrument panel
Outside rearview mirror switch
Radio
Sunroof switch
Sunroof tilt switch
Steering wheel control switch - left
Steering wheel control switch - right
Traction control switch
Transmission shift lever position indicator
Window switch - driver
Window switch - passenger
Window switch - left rear
Window switch - right rear

When the headlamp switch is placed 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 park lamps as well as the dimming control circuits illuminating all components with interior backlighting. All LED and incandescent backlighting turns ON at the dimming level indicated by the instrument panel dimmer switch. The instrument panel dimmer switch is a momentary type switch and utilizes a resistor ladder to accomplish dimming controls. The instrument panel dimmer switch contains a battery positive voltage reference circuit and a signal circuit from the BCM. When the instrument panel dimmer switch is held in the decrease brightness position, the BCM receives a low voltage signal via the instrument panel dimmer switch signal circuit. The BCM responds by decreasing the brightness of all interior backlighting by decreasing the voltage supplied to the backlighting components via the dimming control circuits. When the instrument panel dimmer switch is held in the increase brightness position, the BCM receives a high voltage signal via the instrument panel dimmer switch signal circuit. The BCM responds by increasing the brightness of all interior backlighting by increasing the voltage supplied to the backlighting components via the dimming control circuits.