A flashing Security light is indicating that the security system on your car is active.
The security light flashes when a programed key is not installed in the ignition, when you insert a programed immobilizer key in the ignition the security light will go out, the light flashes as a theft deterrent
my security light has came on 2 times now,the car looses power and dies but will instantly restart,the (PRND321) also flashes all white when this happens.my theft has already been disabled about 3 months ago.please help!
Bad flasher.
I forgot to tell you after you connect the battery with the key in start position try to start the car after you reconnect the battery
If the security light is flashing you need to change the ignition switch it self. It is likely worn out.
Cycle the ignition on/off/on/off/on and count the flashes of the check engine light. A pattern of two flashes, pause, two flashes would be a code 22.
if it only flashes fast on one side, you have bulb out on that side. If both sides are fast, change the flasher
You replace the ignition cylinder and then turn the ignition (with key) to on position. All dash lights will light up in the on position. After a few seconds only the security light will flash. Leave the ignition on for 10 minutes while the security light flashes. At the end of the 10 minutes the security light will go out. This will be the first cycle of reseting the E.C.M. to read the new cylinder and ignition system replacement. At this point you do this process two more times. This will take proximately 30 minutes. At the end of all three cycles the car should come on. If you want someone to walk you through it E mail me at archuleta67@gmail.com.
Turn the ignition key on,off,on,off then on and count the the flashes of the check engine symbol .It flashes the first number then there is a short pause then it flashes the second number. Example 24 ( two flashes and a pause then four flashes). Look up this number in Chilton's/Haynes or the shop manual for the vehicle
If all other electronics in the car work (lights, dash, radio, etc.) but the car wont start and the security light is flashing, take your key, put it into the ignition, turn it to the on position, and wait a FULL ten minutes before attempting to start the car. If this does not work, try again. If it still does not work, then you will need to take the car to a dealership and have them replace the ignition switch and replace the key (cost: about 200$). If you don't care about the security system, you can buy a transistor at radioshack for about 2$ and have someone who knows what they are doing solder it to the ignition wires to permanently disable the security system.
Sounds like you have a probelm with your security system recognizing your key. Check with one of the really good locksmith that also replace ignitions etc.
The 2003 Pontiac Grand Prix does come with a factory security system installed. If your security system is enabled it should have a "security" light that flashes when the key is turned on.