Radio Amplifier
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The amplifier receives a serial data message from the BCM in order to request an audible warning. The chime alerts the vehicle driver to certain ACC vehicle conditions. The audible chime accompanies a visual indicator as a warning to the driver. The ACC System will not operate if the radio amplifier fails.