I have the original 2 remotes to my chevy blazer for the keyless entry. They have worked for years with no problems. Well, both remotes batteries have gradually gone dead and when I bought brand new batteries for them, the remotesdo not work anymore. I've tried testing the batteries to make sure they were good, and they were, and I have also tried that program (turn ignition on and off, etc) to get them to work, and nothing. Is there anything else I can try????

 

Try standing next to your vehicle and pressing both buttons at the same time and holding them for about 8 seconds the doors will lock and then unlock and then you should be good to go.