Q: Car keeps saying the starter is disabled

It sounds like the new key needs to be encoded with the powertrain control module (PCM). The original key has a resistor in it with a specific resistance value. If the PCM sees a different resistance value, it will disable the starting system. This is the theft deterrent in action. Hopefully, you have a new key that has a resistor in it. If so, the new key will need to be initiated with the system.

Doing this on your Cadillac may require a professional scanner that is usually very expensive. On most GM vehicles, there is a key relearn procedure that does not require a scan tool. I have used this procedure on many other GM cars and some Cadillacs. Sometimes this works and other times it requires the scanner. The only way to know for sure is to try. The procedure is as follows:

1. First, you will need to have a good battery and/or access to a battery charger.
2. Then, turn the key on and leave it on for ten minutes. The security light should stay on for ten minutes. When it turns off, you will have one minute to cycle the key and repeat this step two more times.
3. Repeat Step 2.
   
4. Start the car. If it starts, this procedure was successful. If not, you will need a professional scanner.

If you need any further assistance, I recommend contacting a professional in your area with the necessary equipment to do this for you. Or, if you’ve encoded the new key with the PCM and are still having problems, you may want to consider contacting a certified technician, such as one from YourMechanic, to diagnose and replace your starter. Good luck!