Did you get a reply to your question? I have a 2004 Camry with a similar problem. In our situation, the horn keeps going off and won't start. We thought it might be the factory alarm but can't figure that one out. It was working fine and then we went to start it one day and it didn't work. We took it to Auto Zone and the battery was pretty dead. We had the battery charged and everything else checked out fine. This was fine for 2 days now we're back to square one. Any idea?