Car wont start

My wild guess would be that if your key is chipped, then you may have to re-marry it to the ECU, if that takes place in the actual design of this car. To completely remove security feature you may have to re-flash engine control module (ECU) I am not quite sure of design of this particular car, you may have to check with experts...

unhook battery 15 min hook back on lower driver window put key on ignition just bump the engine and wait until security lit stop flashing turn key off do it again 3 times once lit goes off crank engine an should start if lit wont go away or flash while cranking you have a security issue at switch or bcm now need a scanner capable to look at the security data

im not sure but my jimmy will run great then i go to the store and come back out it wont start i wait 15 min and it starts right up , my problem was security sensor , see if the security light comes on when it happens if it does i would look into that

body control modual has bad connection at connectors

u have to reset the PC car
first step .. try to start the car ,, and sure it will not start and the thefth system light will turuned on
soo keep the switch opened until the thefth system light stop .. it will take 10-15 min
switch it off for 10 seconds
again switch it on but without starting the car .. and wait for 10 min "not less than 10 mins,, if little more no problem" .. do the same thing one more time ..
finally switch it off .. wait for 10 seconds and start the car ..

If it is a security issue a code will be stored. Until you check that a code is not stored then all suggestions will be a waste of time.
You really need a diagnostic scanner hooked up to see whats going on.

sounds like your security was tripped somehow..

1. turn the key to start the engine then immediatley release it to the on position. Keep it on the on position for 15 min. Watch the security light. The light should go out in 10-15 min. Turn the key off and wait 10 seconds.

repeat that same process 2 more times. After that your car should start. i had this same problem. Mine is a 03 but im assuming yours has the pass lock security on it also..

Passlock system is crazy, GM should be terminated for good just for coming up with this system and putting it on all there vehicles. to me this is by far one of the worst goofs of all time, but I think they had it planned as a money making scheme to begin with...Anyways if your security light on the dash is flashing first try unplugging your battery and wait a few minutes and hook it back up. If the light is still on it wont start. proceed to step 2, turn your key forward all the way to the farthest on position. Now go have a drink talk on the phone whatever just wait 15 mins and come back. If the security light is now off, turn the key off and wait 5 or ten seconds and your car should start.. If the light is still blinking or staying on it wont' start. step 3...try a different key if you have one and do the 15 min mess all over again. Hope you have a strong battery. If that doesn't work you probably will need to get your ignition key switch replaced. I Buy them at local part stores, Orielys and off ebay for under $100. The GM dealer wants about 500+ to do this. **** on them, do it yourself or get a friend to.

Looks like the TDM in the security system (VATS/PassKey) is having problems, it's typical on those cars and it can get worse till the car wont start anymore. You can find a great write-up here: http://newrockies.ca , it was the only thing that saved my Park Avenue.

sounds like your passlock sensor on the ignition barrel is faulty. you will have to go to the dealer to have it replaced because of the programming after replacement.