I have a 99 Accord Coupe with the same problem, my code doesn' t work. My local dealership gave me the code over the phone with the serial # I found inside of my glove box but the code didn't work. Took to same dealership to have the stereo pulled out to get the serial # off back. It was the same one as listed in the glove box so it gave the same code. They said it must be an internal problem with the stereo and that they could send it to the mfg. for me to be fixed for a cost of about $300 and I would get it back in about a month. Screw that, I can go buy an aftermarket stereo for $100 and have it installed the same day for free but I don't want an aftermarket stereo. I want mine to work again. It worked fine before the battery had to be replaced so why now does it suddenly have an internal problem that only the mfg. can fix. If anybody knows why the codes they give us don't work please advise.