I have a 98 Deville and I use the keyless remote to lock and unlock the car. But there are times when I go to unlock the car with the keyless remote it does not unlock. I have changed the battery in both factory keyless remotes. I have been to a caddy dealer and all they did was charge me for two new remotes and a $99 diagnostic fee, and the problem continues to happen. I have to use the key to gain access when the system will not unlock. In September 2002 I changed the factory deck out for an aftermarket deck. I realized that I lost my chimes and steering wheel radio controls, but could this be causing my alarm problems? Please could somebody help, this has gone on long enough.