This Preliminary Information communication provides information to the technician about vehicles that have Unable to adjust radio volume, Radio doesn't retain previous station after an ignition cycle, displays 87.9 FM and clock 12:00 after ignition cycle, display randomly locks up and Heater-Vent-Air Conditioning displays only HI or LO when changing temperature, loss of radio presets, OnStar interface - screen doesn't return to previous selection after an OnStar call is made. Technician will need to update the radio. Technician will need to update the radio he latest calibrations available in TIS2WEB.
