Circuit/System Description

WARNING: This page is about a different car, the 2011 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

The steering wheel control switches duplicate the function of the primary controls of the associated cellular, entertainment and navigation (radio) component, through a network of momentary contact switches and a series of resistors. Depending on the vehicle cellular, entertainment and navigation (radio) option, a serial data gateway module (up level radio) or a standard radio (base radio) supplies voltage to the switches and monitors the return signals. When a switch is pressed, a specific voltage drops across the resistor unique to that switch. For the up level radio, the serial data gateway module identifies the switch selected and sends a serial data message to the cellular, entertainment and navigation (radio) component controlled by the switch, activating that feature. For the standard radio, the radio identifies the switch selected and activates the selected cellular, entertainment and navigation (radio) feature.