i got a 2013 TL about a month ago, it only came with one key, so I order another key online and had a locksmith cut and program it. Been using the new key ever since, couple of days ago, for whatever reason I try the old key to start the car, but it will not start the engine, show green key light on dashboard, which I search is the key immobilized feature.before I got the new key, the old key was was working. Any reason why the old key not work anymore? Would programming the new key knock off the old key? As there is suppose to be key #1 and #2.

 

When a key is programmed is clears any previous keys. The old key(s) must be re-programmed with the new key(s).