This Preliminary Information communication provides information to the technician for the radio locking up usually after an Onstar® turn by turn route. Engineering is aware of the concern and is working to release software to correct the concern. If the concern happens it is normally corrected by turning the ignition off opening the door to cancel retained accessory power and then restarting the vehicle. If the concern is still present after the ignition cycle it may be necessary to remove the radio?s fuse for 2 minutes and reinstall. Communicate to the customer that General Motors is working on a solution for this concern.