Thread: Security light blinks

I have a 2000 Grand Prix that recently didn't want to start. It started for a second then it dies. I was able to start it after going thru the re-programing procedure specified in the owners manual, however, the SECURITY light is blinking once teh car starts and it remains blinking it, never shuts down.

Went to the dealer and they told me that Theft Module needs to be replaced and e-programed, they quoted me a ball park figure of $450, however, they do not have the part and do not know when will they be able to order it since the part is on a backorder.

Most of the time the car starts fine but the security is blinking and occasionally it wont start at all.


I was wondering if anyone has by-passed the module, since I am not concerned about the theft at all and would like to know if I could just paypass the whole PassKey III module and get rid of the anoying Security light.

Thanks in advance Dan

Had the same problem when my car got re-keyed because someone stole all the keys and remotes for a bunch a cars from the valet stand in the city, but that is another story. Went to the dealership and had all the door, trunk, and ignition tumblers changed as well as got new keyless remotes. As I was pulling out of the dealership the security light started flashing. Basically the dealership did not reprogram the PCM to recognize the new keys. Remember that these cars, as do most now a days, have computer chips in the key that communicate with the on-board PCM. If the key does not have a chip, our has a chip with a different code, the PCM will not recognize it and it is not supposed to start. With a key with no chip it will not start, just turn over and die. With a key with a chip that is new or different you will experience the problem you are having. It will run sometimes, but the security light will flash, and other times it will not start or run at all. Not to say it is not a bad Anti Theft Module, but it is probably a simple reprograming of the PCM. Someone on here with more PCM tuning can probably be of more assistance in that regards? But, be careful driving it, it may finally stop starting or running and leave you dead somewhere. You probably want to have that addressed sooner rather than later if this is your daily driver. Just be careful if you have a re-programmed PCM, the dealership will down load the OEM settings and blow away anything that you may of had customazied.