Have you resolved the issue with the navigation. I have a similar problem. I had my battery replaced by an independent mechanic and ever since the radio and navigation do not work. Lexus charged me 850 dollars to do a diagnostic and they say the whole head unit needs to be replaced at a cost of about 5k. I am not doing that. Of cource the mechanic who replaced the battery says they did everything properly when replacing the battery. Anyone else have this issue and how did you resolve it?
Thanks
Anthony
