FleetMech7

On the DEA700 radios, you need to access the “secret menu” to disable the “LDWS” (Lane Departure Warning System) option to stop radio mute when in reverse. At least that has been true for the trucks I have worked with. To access the menu, you need the key on, radio off. Press and hold the 6 button for about 3 seconds, then press and hold the 6 & 1 buttons for 10 seconds. The menu will display and you have to scroll down to the LDWS parameter, select it and then select disable. Hope this helps.