HiCustomerThanks for using justanswer.com
With the anti-theft light blinking you could have 2 possible problems. Either your anti-theft sytem is malfunctioning or the main computer (pcm) is malfunctioning.
If when you turn the key and the check engine
light comes on then its most likely that your computer is ok. A computer problem is pretty rare but it does happen.
More commonly you probably have a problem with your key. In your key there is a computer chip. When you turn the key the car analyzes the chip. If the chip is the correct one for the vehicle then the computer will start the car. If its the wrong chip or there is no chip (say a screw driver) trying to turn the cylinder then the car will not start.
Now there is a couple of components that operate in the anti-theft system. A key, Transciever, and HEC module. The key contains the computer chip, the transciever reads the key, and the HEC module processes the info and tells the pcm to start the car.
The best way to diagnose this problem is to have a scan tool that can read the codes stored by the HEC module. Anytime the vehicle won't start due to an anti-theft issue, the HEC will store a code describing the problem.
Some independent shops may have the scanners to do this, most wont.
Unfortunately the Dealer is probably your best bet. They have the equipment to do the job right, also if it needs a new key then it will have to be programmed to the car. Which requires the scanner the dealer has.
I hope this information helps you. If you need more just reply back on this page. We can go back and forth.