When I bought it I really got so excited that I maybe didn't check a few things. They gave me a 90 day warranty so I hope they will cover whats wrong. The air comes out mostly out the floor vent no matter what setting it is on, and does not come out the defrost at all. 2nd thing is the Tire pressure light stays on. So I get out and start to check tire pressure and notice that the tires are pretty worn, but have some time left, then I notice 2 tires have plugs in them right in the corner of the sidewall. 3rd prob is when sitting at a traffic light in drive there is a pretty bad vibration and I can watch the steering wheel vibrate.....maybe this is normal but it seems the idle should be up maybe 200 more rpm and it would go away........no check eng lights and it runs like a champ...Still love it either way. Wish I got one of these a long time ago.

 

I'm a new owner to the H3 as well and having the same issue with the TIRE PRESSURE LIGHT being on when you first start the car but once I go on the highway and drive for a bit it turns off. Tires look to have sufficient air in them. Let me know what you find out ... Thanks..

 

Sounds like your tire pressure is just a tad low. Going down the road is heating up the tires, increasing pressure, and the light goes out. Check your tire pressures. Maybe this will help.

 

x2 my wife had the same issue while I was gone and putting a little air in it fixed it

 

couple other things I noticed was that when cruising around 60mph and about half throttle the rpms seem to fluctuate quite a bit.....and just one more thing LOL......I dont think my gas gauge will go below a quarter tank....ok thats it I swear LMAO!!! maybe just over sensitive to the new ride. I was a service advisor for many years so Im pretty familiar with cars but never worked for a Hummer dealer....So some of these things maybe just a characteristic of the Hummer....

 

You have a tire pressure gauge? You might want to use it, works a hole lot better than eyeballs.

TPS problems are commonly caused by a tiny variation in PSI, set all four tires exactly the same cold. There are a zillion threads on this, 38 PSI works, 35 is too low IMHO.

 

If the truck is 4-5 years old it should not be uncommon that the batteries in the sensors crapped out. Only solution is to replace the sensors or to disable if possible. I did this in my 04 touareg and got them disabled

 

Most all of our H3s use Schrader Electronics TPS and they have a 10 year/150K miles battery life. Any suppliers of GM TPMS must meet that spec as well.

There is no true way for an owner to disable the TPMS so we are basically stuck with it.

 

Not really worried about the Tire Pressure light. I gauged them all and its off now. Was more concerned about the other issues...On a side not I drove it 4 hours today and could drive 4 more with a huge smile on my face...

 

What year is your H3? If its an 06-07 then the vibration is most likely from all those years of crappy gas! Run some Techron additive in the tank. Whats the mileage? Perhaps who ever owned it before you did not clean/replace air filter as needed and you need to clean your MAF sensor. I had the same vibration in my 06 @ 50k miles and performing the things above made it run like brand new! Oh depending on your mileage some new plugs never hurt.