Component Description: OnStar®: Notes
WARNING: This page is about a different car, the 2008 Saturn Sky and 2008 Pontiac Solstice. However, it is still accessible from the selected car via links, so may be relevant.
OnStar® equipped (RPO UE1) vehicles use the radio and speaker system for voice communication from the OnStar® operator to the vehicle. Voice communication from the vehicle to the OnStar® operator is through the OnStar® microphone and module, which is not a part of the radio system.
The radio receives a mono audio signal from the VCIM via two cellular telephone voice signal circuits. When OnStar® begins operation, the non-OnStar® radio audio is muted and the fade control is adjusted to the full front speakers. OnStar® audio then can be heard over the vehicle front speakers. The radio volume control can then be used to adjust the volume to a desired level.