My key fob has been messed up for years so I bought a new housing off of ebay and switched out the internals to the new unit.

I programmed the fob with the usual method and the alarm works as far as unlocking and locking the doors. The problem is with the key itself, the car would start and cut off and the car with the key immobilizer light would flash. Then I used the Valet key and no issues and then used the original key and now the car would start and not shut off but the immobilizer light still flashes. This is the same key just a new fob housing. I tried to use the search function but came up with nothing relevant.

Thanks!!!

 

I fixed it!!!!

Everyone says that the RFID tag is in the tip of the key, but it is actually in the FOB housing. What I did was take the glass tube (smaller than a Benedryl Capsule) in the old FOB housing and glued it into the new housing. You have to be very careful when extracting the tube from the old housing since it is a thin glass but I ate away the glue with an exacto knife until it was loose enough to carefully pry out with a small screwdriver.