The security light was not on, the mechanic ran diagnostic to get the service engine soon light off (car running) when he was done we left (car still running... never shut off) and noticed that the security light was now on. When we got home, we shut the car off, and later when we tried to leave, the car started for 3 seconds and then shut off. Security light flashing.
What was the initial diagnostic check being done for?
Will the engine turn over?
1. Perform a security system relearn. 2. Let the vehicle sit for more than 10 minutes with the key off. 3. Attempt to start the engine, leave the key in the run position monitoring the security system indicator. 4. After 10 minutes, the security indicator will change state (turns off). 5. Turn the key off and wait 10 seconds. 6. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. 7. After the second 10 minute timer has expired, turn the key off for 10 seconds. 8. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. 9. After the 3rd 10 minute timer has expired, shut the key off for 10 seconds. 10. The security system will relearn on the 4th starting attempt and the engine should start and run.
You are right the problem will happen again at some point, the repair for this would be the ignition lock cylinder.
So either way I just need to take it to a dealer... but I want to make sure I am not getting screwed. I really don't feel that the security system module is broken and I think that the car thought it was being stolen because something was touched or whatever. Reading online, there was a blog indicating "if your car has passkey3 system, you cannot relearn your keys". Mine does (PK3 indicated on my key). So this would explain why the relearn would not work for me. in this case, if the system was just tripped, the relearn doesn't work, and the security module isn't broken, what is the fix? Can they reset the code or ??? Every dealer I speak to indicates they want to just replace my module, which probably would fix the problem, but isn't cheap!
PK3 can be relearned with the procedure I gave you. I did give you some bad info as far as the lock cylinder, I forgot that these do use the theft deterrent module that goes around the lock cylinder. I do not believe this module is really that expensive but I do not have a price for it. Pic below of the module, It is #2 in the pic.
If one of the keys is bad and you do the relearn with that key it will not relearn, if the key is the problem and you use a good key the learning process should work and the light would go off. If the key is not the problem and the module is the problem it will not relearn with either key. If the problem was caused by the diagnostics/ clearing the history it would not have taken 10-15 minutes later it would have happened right away.
It did happen upon clearing of the diagnostic.. immediately.
What I meant was that we drove for 15 minutes.. never shut off the car... the mechanic walked up, plugged in the diagnostic tool, we talked for like 5 minutes and when drove away, we noticed that the security light was on. Is it possible clearing the history with the diagnostic tool caused this? This is the reason I don't think something is broken... that it just "thinks" it is stolen.
I guess what I am wondering is, have you ever seen the module go bad while a car is running. In my scenario, what are all the possible causes?
I have fixed many of these and as a tech you never really know when the problem started because you never know if the customer actually seen the light on or sometimes they do not know when it came on. All of the possible causes are, the key, module, wiring problem, power train control module. The most common is the module and a wiring problem in the steering column (which any good tech would check if trying to fix this problem) because there is a technical service bulletin for this problem but I rarely see it.