Hey all you Hummerites,

I got my 2008 H3 about 2 months ago and never had any problems with starting...until it got cooler [mind you not cold, just cool (40 degree weather)] and my H3 won't start, it turns over and makes a little whining noise like it's about to, but nothing.

First, my dad and I replaced the battery thinking it was the obvious solution, but nope. Went out the next morning while it was approx. 50 degrees and it wouldn't start, just turn over and the check engine light and security lock light in the lower right dash corner would come on. Although, my dad came back later in the afternoon when it was about 70-80 degrees and the Hummer would start right up like it never had any problems. I then did some research and found out if could be blown fuses, the ignition switch, battery terminals, or crash mode seats. But why would it start later in the day but not earlier. I've heard that if you come back about 10-30 minutes later it would start due to the anti theft mode, sat in the Hummer for 11 minutes one morning, and the light did NOT go off and wouldn't start. Leads me to ask, is it the cold weather causing something to short or not work properly? Any possible solutions would be greatly appreciated!

P.S.- We took it into the dealership and they claimed to not find anything.

 

I would follow the course of action you identified starting with the battery terminals. Those could throw the whole system out of whack. Why will it start sometimes and not others? Because thats the nature of electrical problems; to drive you crazy. I wouldn't get to hung up on trying to figure out what conditions it happens under until you have ruled out some of the basics.

 

cranking and starting seem to get confused here.

you can crank all day and not start.
if you turn the key and the starter engages and the motor rotates,the syatem is "CRANKING" that means the battery and connectors and associated parts are good,,NO REASON TO CHANGE THE BATTERY OR CABLES!!!

if it CRANKS and doesnt start/run,that means when you let go of the key the engine stops rotating,it aint running,you cant go for a ride.
if it cranks,,,and it dont run its a gas/air/ignition/computer problem.

if the lights /radio/fan/horn work and it "CRANKS" the batt is ok
if someone says it cranks and dont run,dont tell them about your favorite battery or cables!!!,,,and i have no idea why a slight temp change would change anything,it should run from +110 to-40!!

no codes??

 

i would drop it off at the dealer and let them try to start it early the next cool/cold morning and then see what they have to say. is it still under warranty? keep us posted!

 

Hummer didn't start again this morning, still cool as usual. It cranked, but didn't start, lights came on and everything, but no start. Called the dealership yesterday and let them know about the security light and check engine light coming on, dropped the Hummer off and they said they would know what the check this time. Will keep you guys posted! Thanks for the replies.

 

I remember a white H3 in Iraq last year and it was around 140 during the day.

 

Oh and I must add that I tried the 10 minute wait procedure, but nothing. I don't know if that only works for the 06 models since I've heard of people waiting 15-30 minutes.

 

Some updates:
They replaced the ignition switch...worked fine for a couple a days then wouldn't start Monday morning, brought it in and they said it was probably the BCM and replaced it, now the real test is the rest of this week. Will keep you guys posted.

 

Thanks for posting an update!

Too many people ask for assistance and never come back to post an update of what was done and if it fixed their issues.

 

computers all over the place. im not doin research at 1am!, but which one controls the engine?? the body control module?, pcm?