Just wanted to pass on this information in the event someone else has this same problem with their GM vehicle. Here is the symptom:
Symptoms: ======================================= Engine starts but stalls 4 seconds later. Security light is on. Vehicle is undrivable. Tempers flare. Yell at 'stupid car'. =======================================
I found the problem to be with the Pass-Key III system. For some reason unknown to me... it caught a case of alzheimers and forgot all key transponders that worked just fine hours earlier. I searched everywhere on the net, but was unable to find the procedure to have Pass-Key III relearn the master keys transponder codes. I am posting the procedure here so that others do not have to pay to have their cars towed to the dealer to have this pathetic security system reprogrammed.
Procedures: === Relearning the Master Key's code === Using the Key with the characters PK3 M (M stands for Master Key). Insert Key into ignition and turn to Run position (do not start car). Security light will blink for 10 minutes. When it stops blinking, turn key back one click (dash lights will go off). Within 2 seconds, turn key forward to Run position. (This procedure is repeted 3 times, for a total of 30 minutes) After the third time, turn the Key to Off and remove the key from the ignition. Re-Insert the master Key into Ignition and start the car. The Security light should go out after a few seconds. (If light stays on, you messed up the procedure, try again)
=== Relearning other Keys === All Secondary Keys should be moved away from ignition switch. Insert Master Key into ignition and start vehicle. Ready the secondary key in your other hand. Turn off and remove the Master Key from ignition. Within 2 seconds, insert the secondary key and turn to Run position. (do not start car) when security light turns off (1-2 seconds), turn key to Off for 2 seconds. Turn key to Run and wait for light to go out again. This process should be repeated a total of 3 cycles of Run-Off. Remove secondary key. To test the key, re-insert and start car. Light should go out within 1-2 seconds.
=== Have Pass-Key III relearn remote FOB codes === At this point, It wouldn't be a bad idea to have the brain dead car relearn your remote keyless entry FOBs codes all over again. Fortunate for us, this is not that big of a deal... Press and hold the LOCK and UNLOCK buttons on your FOB for about 5 seconds. When the Horn sounds with a happy little 'toot', all is good in Pass-Key land.
I hope this post is able to save someone a few bucks and a lot of time waiting at the dealership. I just couldn't imagine what would have happend if this this lost it's mind while it was not in the driveway.
Good Luck, Mike Gercevich