This was a pain in the ass. I was fortunate that it happened in my driveway instead of out on the highway. Approximately one week before the major breakdown an indicator light appeared on the dashboard that looked like a padlock and just stayed lit with no blinking. I had no idea what it meant and had to research it on the internet. I found out that it was some sort of a security system that some rocket scientist engineer figured the vehicle needed so I ignored it. All of a sudden one evening my vehicle just wouldn't start and I initially thought it might be the fuel pump because it turned over and sounded like it wasn't getting any gas. I had no choice but to contact my mechanic and have the vehicle towed which required having to have it put on a flat bed. My mechanic hooked it up to his computer and found the problem was in the security system. Once he installed a new ignition switch the problem was solved. I wish these automotive engineers would realize that designing features like this security system is subject to failure that usually doesn't happen when the vehicle is under their warranty. If I would have been traveling when this happened it would have been devastating fortunately I was in my driveway.

Hummer H3 has GM's trusty PASLOCK II anti theft system . This system disables the fuel system when a false key is detected. The H3 is built with a very weak ignition switch. If you like to hang your keys, pictures, icons, your coat and jacket on the key chain with your ignition keys while in this switch , be ready to be stranded, at least until the system reset after 10 minutes. Hope it starts then. I never hang anything on my key chains except the key and the remote FOB. I tried a passlock bypass sold on Amazon that tricks the passlock system into ignoring the signal to the BCM. It failed to fix the problem. What worked for me was taking it to the Nearest GM Dealership and replace the weak/cheaply made Ignition switch. After this , I never had the embarrassment of Hummer just cranking over and not starting. This could be a safety concern for women and females traveling alone. This system ,if it fails, could potentially put someone in harms way. Hope this helps some frustrated person. Just stop trying to fix it your self, save up the funds and report to your nearest GM dealership..They are waiting on you and more than happy to take your money. Again this is another Manufacture defect that customers are shelling out to fix.