I recently purchased a 2009 suburban ltz and it only came with one key. I purchased two circle plus keys and two key fobs off of ebay and had the keys cut. I was able to program the key fobs with no issues, but each time I try to program the keys, The lock light and the "Service Theft Deterrent System" don't go away.

My procedure is as follows: I turn the ignition to ON with a working key, wait for the security light to go out, and then insert the new key and turn the ignition to ON. I was expecting this to be quick, but I've waited a minute and the lock light and message do not go away. How long should I have to wait for the new key to be picked up?

I can however start the car with the original key and immediately start the car with the new key, but the theft message and lock light stay on while the car is running.

I've also tried the procedure after disconnecting the battery for 15-20 minutes and touching the terminal wires together.

How would I know if the car is already programmed with 10 keys? I was going to try the relearn procedures from here http://my.cardone.com/techdocs/PT%2077-0011.pdf, but I'm worried I'm going to put the vehicle in a state where none of the keys will start it. Thoughts? I'm thinking I may need to just go to dealer.

Did you purchase this from a dealer? If yes, then they should have done this for you.....

How were you able to program the fobs without a Tech II?

The procedure you are doing seems right.....install a Master key, SECURITY light goes out, then insert new key, and SECURITY light should go out within seconds.....

I seriously doubt 10 keys could have already been programmed, but I suppose anything is possible....

I purchased the vehicle from a GM dealership about a month ago. The Suburban has an option that you can select to add key fobs, which is how I did that. If there haven't been 10 keys programmed, then is the only other answer that the circle plus keys I got from ebay are no good? The seller had tons of good feedback, but that doesn't mean I got working keys I suppose.

When doing the key learn, try starting the vehicle with the master key, then insert your new key and start the vehicle within 5 seconds. Hasn't failed me yet. Also does the new key show Pk3 on the base of the key.