I have a 99 Silverado with 174k on it. It is my daily driver and quite beat. A few months ago my keyless entry stopped working. I thought it was a dead battery, so just figured I would get around to buying one. Well I finally remembered to get one and it didn't fix the problem. I have another remote that has very little use on it, and that one doesn't work either even with a new battery. Does anyone have any ideas?

 

On your unused remote try holding down the lock and unlock buttons at the same time for 20-30 seconds it will respond by honking horn and locking and unlocking the doors. Put a new battery in it first.
The above procedure is called a re-synchronization procedure to match and reset the rolling code algorithim between the bcm and the RKE remote.

 

It works now. I put another battery in the remote I never use, and it worked for some reason. I tried the remote I used to use, and it didn't work. I did the re-synchronization as you suggested above, and now they both work. I thought for sure it would be a rusty connection somewhere. Thanks a lot.

 

No problem