My battery died, and we replaced it. Had reset the radio code previously, with no difficulty, but this time it didn't work. Used up my 10 trial attempts, and went to the dealer. Service man checked code against radio serial no and it's correct. He suggested pulling the radio ($120) to CHECK the serial no, even tho I told him it had worked before. He suggested I buy a new radio. Came home and researched the problem online. Tried disconnecting and reconnecting battery, entered code when prompted and now have Error Code 1 displayed - again. Not sure what else to try? Any help/suggestions are welcomed!
Did you try retrieving the serial number from here to cross verify the same - https://radio-navicode.honda.com
Is it possible to see the codes in the display when you enter them, perhaps you are entering the right codes but the number keys have some issues.