Originally Posted by DaveSac11789
Any reason why the security light is always on? since i bought the car almost 8 months ago?
maybe someone broke into it a while ago?
i dont even have an alarm so i dont know why its on nor do i know if its at all important
For 96-99 Bonenvilles, the "security" light is supposed to remain illuminated for 5 seconds if the system is operating correctly. If your security light flashes once per second and the engine does not start, it is an indication that the VATS system module has sensed an open, a short, or invalid input from the resistor pellet in the key. If the car starts but the security light stays on, there is a different problem that has a series of diagnostic steps that can be performed. The FSM also says that this could be caused by a malfunctioning power or ground circuit.
Here is the original info I was referring to: