I had 2 of the key/door transmitters for my car but now I can't find the one I've always used, so I pulled out the backup and it won't lock/unlock the doors with the transmitter. I went and bought 2 new batteries for it and it still doesn't work. Checked the battery contacts and cleaned them, still no luck. Any ideas why?

 

There is a sequence follow to sync the key with the car,i think you lock,then unlock the car,manually with the key,then it programs the keyless entry

 

I'm getting a spare key on Friday so I'll be able to test your theory. Thanks.

 

You were right! I locked and unlocked the door a couple of times with the key and then the transmitter worked. No idea how that process works to program the the key, but who cares, it works!

 

I can say the same.

Works perfectly.

 

I'm glad to be of service