Sevice Theft System dispays in dash info display, tried the 30 min key relearn

The passlock system is acting crazy. There is a way to bypass is if your car is not working, however...the BCM (body control module) is what tells the PCM (Computer) to run or turn off the fuel. If the BCM is bad...the bypass will not work to start the car. About 3% of people with the security system problems have a bad BCM...while it's rare, it does happen. Hope this helps

I have a 93' deville, was experiencing the same problem. I wouold get in car and it would not start. I could try again later in the day and it would start, drive around all day running errands with no problems then suddenly, no start. I found that Auto Zone sells a repair kit, just a matter of finding the ohm's put out by chip and then making a bypass module what I was told. HERE IS THE "SOUNDS STUPID" portion..... I took a small fingernail file and just gave each side of the key a couple of swipes and I haven't had a problem with starting in 2 months. I hope I didn't just jynx myself. The light is still on but it starts. worth a try for a temp. fix.