06 LT 3.9 Remote Start
 

So my Monte came with no key fobs at purchase. I purchased 2 with the flip key and programmed them to my car and they worked perfectly. So one day I step out on my balcony to remote start the car and the park lights and horn flashed and sounded simultaneously but no start. So now anytime I try to remote start it the horn blows a few times and then the alarm sounds if I don't press a button on the fob to stop it. Can anyone give any insight?

If I read correct, these replacement fobs DID work with the remote start and recently that changed? I have heard that supposedly the factory remote start will not activate if the car has an active check engine light, does yours have that situation (an active check engine light I mean)?

No check engine lights at all.

Off hand, I am not sure. Not sure if it is something that has failed in the fob OR the car.

Have you tried reprogramming it??