Thread: Security light flashing

I have an 00 GTP and just got done swapping the engine in
it. Started engine up and now I have a security light that stays flashing for 10
min or so before it goes out. Car starts up, runs fine, and no codes. Did the
security 30min relearn procedure and that didn't fix the problem. Where to now?
Didn't have this problem until after engine swap.

No same PCM.

I'm starting to think this doesn't have anything to do with the engine swap, but more with the battery being disconnected for a long time. When I disconnected the battery changing the Cam position Sensor before, it did something very similar, but would die after 3 secs.

I'm also thinking I may have done the relearn wrong. I started this process right after shutting the car off, without waiting at least 30 seconds. Below is the relearn procedure I followed. Do you think not waiting after shutting the car off and starting the procedure could have effected the process?

With a master vehicle key, turn ON the ignition, with the engine OFF.
Observe the security indicator. After approximately 10 minutes, the telltale(security light) will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes. Important: The vehicle learns the key transponder information and/or passwords on the ignition switch transition from OFF to RUN. You must turn the ignition OFF before attempting to start the vehicle.

With a master vehicle key, start the vehicle. The vehicle has now learned the key transponder information and/or the ECM has now learned the fuel continue password.
If additional keys are required to be learned:
Adding Keys Important:

•	To initiate, this procedure requires that a learned master key be available.

•	A total of 10 master keys or valet keys may be programmed to a single vehicle.

•	This procedure adds keys only. The procedure does not erase previously learned keys.

•	The keys to be learned must duplicate the mechanical cut of the current key.

•	If more than one valet key is to be learned, immediately precede each valet key with a learned master key.

1. With a previously learned master key, turn ON the ignition, with the engine OFF.
2. Turn OFF the ignition and remove the key.
3. Within 10 seconds insert the key to be learned. Turn ON the ignition with the engine OFF. The vehicle has now learned the new key

So any idea of why the Security Light is flashing for the first 10 minutes of drive time? Everything I could find on line states to try the 30 minute relearn process to get it to stop. I'm just trying to figure out what is causing the light to flash and fix it.

Originally Posted by Scottydoggs

not really sure, but if its running thats always a good thing lol

Isn't that the Truth! Swapped motor is running perfectly, just sucks the damn light is flashing now. I did scan for codes, with one of the Innova code reader and didn't have any. I do not have a Tech 2.

My 2000 GT has been doing this for years. No idea why. Car runs fine and security light stops flashing after 10 minutes. I figured it was just my car's way of reassuring me that I'm secure. :-)

Originally Posted by 4fanintexas

My 2000 GT has been doing this for years. No idea why. Car runs fine and security light stops flashing after 10 minutes. I figured it was just my car's way of reassuring me that I'm secure. :-)

LOL I hate having things not right. It's just weird that it just started doing in out of no where. Right now if it doesn't relearn again I'm siding towards the theft deterrent module being the issue. Funny thing is there are many posts on line about this same problem, and nobody ever posts back on what finally fixes it.

Originally Posted by Scottydoggs

try pulling the battery for a hour or so, might reset things and be ok when re connected. never know, electronics are goofy sometimes.

I tried that over night. No change.

Well it's definitely not a relearn issue, tried 3 times last night. I'm starting to wonder if maybe I missed a wire/ground during the engine swap.

I find it curious that this happened after a motor swap, but then previously when I had the battery disconnected to change a cam position sensor the security light was flashing, car would start and die with in 3 seconds with the master key, but would start and run on Valet key. I got a new key and did the relearn to fix that problem, but all the old keys also were able to be relearned again, so I don't believe the key was the problem. So now after reconnecting the battery this time, the security light blinks but the car starts and runs fine with the light going out after 10min. I'm surprised there hasn't been a class action suit against GM over this issue. There are thousands of posts on the internet, but no one ever posts what the exact fix is and the cost of the repairs range between $100 to $1000 with some never being fixed. Ridiculous.

Here's a little interesting update. I swapped out the theft deterrent module and that didn't solve the flashing security light, so out of curiosity I disconnected the theft deterrent module plug and the security light is not flashing anymore and the car still starts and runs. LOL I realize it's not supposed to start and run, but it does and I don't have to look at the light flashing for 10min.

Anybody got any idea of what is going on with it?