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2007 H3 idles rough intermittently

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  #11  
Old 06-21-2016, 09:26 AM
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X2 on what Doc says. Once you cut the old terminals off and take a close look at them and how they work, you'll just shake your head and ask "huh?"

And the encoder motor is part of the 4WD system (replaces the manual transfer case shifter); it isn't causing your problem.

I, too, had a similar issue with SVC STAB SYS/TRAC FAILED/REDUCED PWR messages, and the rough idle/die situation. Usually, clearing the codes with a scanner would solve the problem, temporarily, but not always. I finally broke down and replaced the Battery Cable Ends, thinking "why not?" Amazingly, I haven't had the issue since.

So try that first. These H3s are extremely sensitive to voltage variations and they have several 5v reference circuits that cover alot of different systems and components. Any change in voltage can cause all kinds of weird glitches in the system. Once a "glitch" hits, it is like a line of dominoes; a glitch may cause a reduced power mode, then the computer decides that at reduced power, you don't need traction control, and without traction control, the stabilitrac system gets turned off, and...etc.

Again, battery terminals first, then see. As for the sunroof, if it has leaked significantly, water can foul the BCM, which is behind the passenger side kick panel. That can cause all kinds of problems, too.
 

Last edited by 650Hawk; 06-21-2016 at 09:32 AM.
  #12  
Old 06-21-2016, 10:17 AM
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My bad..... forgot to link to the H3 FAQ section thread.

Here it is: https://www.hummerforums.com/forum/h...what-do-33916/
 
  #13  
Old 06-21-2016, 07:20 PM
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Default Changed out terminals

Thank you guy, I truly appreciate it.

I just put New battery end's on. No go. I went through the throttle body take off again, clean and check for leaks. No go.

Here is video of me trying to start it up.
https://youtu.be/96c7lmLI_2Q


Two things I should have mentioned before. I replaced the alternator with factory OEM GM and the wire harness did not match. The parts number was correct and mounts matched so ended up having to cut it and splicing in one the was able to jemmy in. I've put a voltage meter on the battery get 12.5 voltage and when cranking over it jumps to 13.8 before it dies.

After reading your post about sensitive voltage I was thinking about that. My spliced wire's are a bigger gage wire. Does that change the Om's? Or could it just be a bad new alternator causing this. Would it at lest idle for a while off of the battery?

I'm going to try and order the accelerator kit and eliminate that.

O Yeah! I do have a sunroof and yes it leaks. In fact the day this all happened I just washed it. It was wet on passenger floor board. I don't know what to look for?

Thanks guys
 
  #14  
Old 06-21-2016, 07:38 PM
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Judging by engine cranking speed in video there is a problem with voltage, its cranking too slow for one thing. Im assuming this in the inline 5 engine? Remove the cam actuator solenoid on right side front of engine behind power steering pump area. If any of the screens on actuator are missing you need a new one. If oil is inside electrical connector, you need a new one. Its held in with one bolt and may be a little tough to remove but could be major part of your issue.
 
  #15  
Old 06-21-2016, 08:36 PM
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Default cam actuator solenoid

Originally Posted by HUMTECH
Judging by engine cranking speed in video there is a problem with voltage, its cranking too slow for one thing. Im assuming this in the inline 5 engine? Remove the cam actuator solenoid on right side front of engine behind power steering pump area. If any of the screens on actuator are missing you need a new one. If oil is inside electrical connector, you need a new one. Its held in with one bolt and may be a little tough to remove but could be major part of your issue.
Yes it's the inline 5. I pulled the cam actuator solenoid and all the screens look good, as well as the electcall. I cleaned it and reinstalled it.

Put the battery on the charger. It also had low cranking amps from trying so much. Maybe reason for turn over slow.

I have located the BCM and I don't see any sign's of water or damage, but I don't know what to look for unless obvious. My gut feeling is electrical as well. Where too begin!
 
  #16  
Old 06-22-2016, 10:52 AM
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I'm leaning towards a wet BCM issue.
 
  #17  
Old 07-04-2016, 12:39 AM
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This happened to me and it was the #1 spark plug and coil that fixed the issue for me....it had gotten wet
 
  #18  
Old 07-04-2016, 03:50 AM
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Default BCM is ordered

Originally Posted by 650Hawk
I'm leaning towards a wet BCM issue.
I think you are right, or at least hope. I ordered today from RockAuto, $218.00 out the door. I have lined up a local GM dealer to have it towed too. They said its approx. 1 hr to programs the BCM. One thing I found weird was the BCM comes with 2 keyless entry fobs. Just one more thing the BCM controls?

Lighter note, my H3 key fits the ignition but not the door. I only have the 2 OEM keys. Is this the same for anybody else?

Thank you, guys again, let you know soon as I know.
 
  #19  
Old 07-05-2016, 09:08 AM
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I bought my H3 used, and it came with 2 FOBs and 2 keys; my door & ignition are keyed the same
 
  #20  
Old 07-18-2016, 06:44 PM
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No Go!

Update, I got the new BCM for my H3. Towed it to local, dealer for programming. No change did nothing. Cranks over start for 10-20 sec. and dies (As a reminder).

I did find out that the new alternator I installed is the wrong alternator, according to GM matching it up with my VIN. although it is an alternator for a 06 H3 same motor.

My question now is, could this cause the problems I am having? I will reorder the correct alternator and eat the cost of the other because I foolishly admitted to GM that I installed before matching it to my VIN.(Sucky)!!! 2nd the GM dealership says they can't do any diagnostics before I change the alternator and new harness. They will not touch it until I correct the work I did myself. Also, they suggest I order a new throttle body @ $550 before they troubleshoot my issues. Awful experience with this dealership!

I have found a mechanic that will try and figure this out. ? should I fix the alternator before I have anyone look at it because that might be my problem? Why I ask is I need to tow it from the dealership back home, fix alternator, then tow again to the mechanic.

Thank you again for your time to read and help me.
 


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