Circuit/System Description
WARNING: This page is about a different car, the 2008 Cadillac CTS. 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 is located on the radio/HVAC control panel and is permanently grounded through G402. When the hazard switch is placed in the ON position, ground is applied through the hazard switch signal circuit to the body control module (BCM). The BCM supplies 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 GMLAN serial data message to the instrument panel cluster (IPC) requesting both turn signal indicators to be cycled ON and OFF.