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.

The hazard flashers may be activated in any power mode. The hazard switch signal circuit is momentarily grounded when the hazard switch is pressed. The body control module (BCM) responds to the hazard switch signal input by sending a serial data message to the Lighting Control Module. The Lighting Control Module responds by supplying battery voltage to all four turn signal lamps in an ON and OFF duty cycle. When the hazard switch is activated, the BCM sends a serial data message to the instrument panel cluster requesting both turn signal indicators to be cycled ON and OFF. If serial data communication is lost between the Lighting Control Module and BCM the hazard lamps will default to the current commanded state.

The Dimmer Switch controls the brightness of the interior backlighting components. When the Dimmer Switch is placed in a desired brightness position, the body control module (BCM) receives a signal from the Dimmer Switch and responds by applying a pulse width modulated voltage to the hazard switch light emitting diode backlighting control circuit illuminating the LED to the desired level of brightness.