Pats system?

A rapid flashing security light with the key on is a component failure in the PATS system. Commonly it is because it cannot read the key as a correct key. If you have a spare key try that first as a bad key will act the same way. If not then you will need to take your current key to a locksmith or have one come to you so the key can be tested. If it tests okay, then the next likely item is the PATS module itself. It is inside the covers on the steering column. You remove the two covers then the screws on the module. Then you use the key in the lock cylinder turned to the "on" position. Then use a tool to push the release pin up to release the lock cylinder. Now remove the screws from the module and install the replacement. Reinstall the lock cylinder and check it. Then test to be sure things work. If it's okay reassemble the column.