i used to have the same issue with an f body camaro. i had to carry two keys. if one wouldnt work i would use the other. i never figured out if it was the key or tumbler, i bypassed that security feature with a resistor in the wire that runs to the ecm and it never happened again. Im not reccomennding the bypass on a hummer but it does sound like the sam symptoms.

 

The H3 does not use a "chipped" key, the feedback is in the cylinder housing itself. Try the easy fix first, replace the battery terminals (see pic Below). You can pick both the possitive and negative terminal up from Autozone for under twenty bucks. An easy half hour or less install. Plus if you ever hook up a winch or heavy duty fog lights you have the added power outputs available. If that doesn't do the trick, its your key cylinder tumbler.

 

My wifes 2007 has been doing this the last few weeks. She told me about it happening to her a few weeks ago. I had it happen to me last weekend when I was going to back the truck out of the garage to wash it. Then last Sunday night we stopped to get gas and it happened when we were trying to leave.

I looked at the key and found some black mess in the grooves of the key. I cleaned this out while we were waiting at the pump. She put the key back in the ignition and it started right up. I guess we may have set at the pump for about 10 minutes all total and tried to start it a few times. Any help on this topic is greatly appreciated.

 

Same is happening to my '07 H3. Very random, but at least once a week. The GM service dept advised the ignition switch requires replacement. This will be done in the next few weeks. Will advise if doesn't work.

 

wow that sucks, thanks for posting the question

 

My 07 H3 was doing the same thing. I brought it to the dealer and they had to replace the ignition switch . No more problems .

 

I had the same issue in my 06 H3. It is a little metal pice inside the ignition switch that is causing the issue. If the replace the ignition you should have no issues. We have not had any since they replaced ours. Let us know how you make out.

 

After reading the last post awhile ago and having no issues, I thought good to know.
Well as of tuesday and then saturday and then again today, I have the same problem. I tried the 2nd key on saturday - no start. I changed over the battery clamps - no start. Now everytime it shuts off, I have to get a boost.
So here I go to the dealer...

 

Hey Lucky19942001;204824, I just had the same issue with my battery cables. I went down to the local auto parts store and bought common lead battery cable ends. Cut the cheap azz cable ends off the original equip and put the new common lead ends on. Cleaned and sprayed to prevent corrision and I'm back in business like new. Don't wait on the high priced OEM cables to come in. Took me 30-40 mins lifting hood to crankin and back in business.

 

I had the same problem, randomly not starting (2006 H3), changed the ignition cylinder and had the fuel pump filter changed or cleaned. My car has only not started once since those two things were done. They checked my fuel pump but only the filter was changed.

I have been using only the key, not the beeper thing. Was told it could also be the BCM thing, I am having that done today.

From what I read, it must be either the Ignition cylinder (which would explain why the car starts 10 minutes later, when the theft control times out) or the Fuel Pump (which would explain why this problem occurred in the mornings when engine was cold 90% of the time). The BCM module could also be a factor, not sure about this.