Grasshopper

First response: Although I didn't disconnect the negative battery cable, I did remove the unit from the car for over 30 minutes which should do the same thing. I tried several volume settings including off, then on with no luck. Second response: No nav voice guidance audio

Does anyone know the procedure to reset the 2003 LS430 nav system? I looked on line and found several procedures but they all say to remove the box from the trunk, then remove 10 screws from the rear panel to access circuit boards, unplug a connector, wait, then reassemble but my unit has only five screws on the back and the rear panel is part of the chassis. I couldn't find a reset button or hole, though I didn't remove the side brackets. I unplugged the unit, waited, then reinstalled it but there is still no nav audio. I removed the DVD, powered down, then reinstalled it without any luck. The nav system works fine otherwise and the car audio system works fine too. I checked the settings menu and voice guidance is enabled for all modes. The unit is a Denso U2.

I tried a reply but I think it didn't go through. Here goes again: Do you know the paint brand and part number?