My Cadillac cts 04 won't start... Every time I turn the key it won't even turn over... But the light that shows a car with a lock on it blinks what do I do

It sounds like either your security module is bad or the chip in the key went bad, do you have a 2nd key for the car? Try that if you do.

Try using the instructions for programming a new key. hopefully it works. Here you go.


IF NO OTHER WORKING KEY FOR THE CAR IS AVAILABLE:

1. Put the newly cut Master key into the ignition and turn it to the ON (RUN) position. A "Security" indicator light on the dashboard will stay on for 10 minutes.

2. Within 1 minute after the indicator light goes off, turn the ignition to "OFF" then return to the ON (RUN) position. The indicator light again will stay on for 10 minutes. (DO NOT REMOVE THE KEY)

3. Again, within 1 minute after the indicator light goes off, turn the ignition to "OFF", then return to the ON (RUN) position. The indicator light again will stay on for 10 minutes. (DO NOT REMOVE THE KEY)

4. When the light goes off for the third time, the new key is programmed into the computer and will start the car. Remove the key and then re-insert it into the ignition lock and start the car.

All previously stored codes will be erased. To stop the process at any time, simply remove the key and use an existing key to start the car.

Sounds like the anti theft system is active m try this process. Turn the key on. Do not attempt to start. Wait 10 minutes. Turn key off. Turn key on. Wit for theft light to go off. Now attempt to start.