I have a 2008 Hummer H2, It’s keeps loosing power then stalling and only turning over until its cooled down. Happens faster when driving highway speed but still happens when driving slow. Feels like it’s going into limp mode, and then just dies. I get a stable-track service light along with traction control lights. Occasionally the check engine light comes one. Has new fuel pump , fuel pump control module, crankshaft position sensor, camshaft position sensor, mav sensor, map sensor, new Ecu.

 

what codes when the check engine light comes on?

Neal

 

I believe you may have a failing steering wheel position sensor this usually generates a C0710 code. It is located just above the connection point of the shaft that extends thru the firewall and to the steering box.

Once replaced you will need to probably calibrate the new sensor. On an 08/09 failure of this part will cause all kinds of issues, it can cause traction control to be triggered, limp modes etc. You will need a tech-2 or good scan tool to calibrate the new sensor.

 

Plugged cats? Check pressure on inlet vs outlet side at the O2 sensors.

 

Hi Neal,
There are about 22 codes I can pull off the scan tool. I think the major ones are P0016,P0106,P0011,P0711,P0776,P0796,P02714, and a few other codes. I have replaced the camshaft sensor and crankshaft sensor? And it has a new fuel pump and fuel pump control module.
When the engine stalls, occasionally I'll have the engine light come on, but not always. Sometime the TC, and Stabilitrak warning message comes on. The engine then will not start again until it has cooled over night, and then starts right up, without any warning lights.? Would a transmission controle module cause all this?
Thanks for any help
Steve

 

Thanks for your reply, I have not seen that C0710 code pop up? Would a failing steering wheel sensor throw any other codes?
Steve

 

Plugged cats. Have you check out my recommendation yet?

Plugged cats are known to cause all sort of random codes. And a lot of them. All seemingly unrelated. Dude, if you are getting so many codes, do you really think there are 22 things wrong with your truck? Nope.

The hint there is that they will cause all sorts of engine codes and fuel codes, because the engine can't breathe. Sometimes, if you get lucky, your scan tool will pick up the right or left bank misfires, depending on which side is plugged.

Unbolt your cats and put in a test pipe, and see if that fixes it. Or do the test I told you to perform. If that is the issue, problem solved.

If not, then you have some other serious engine problems with 22 codes, and best to send H2 to recycling, LOL!

 

Finall,
I'll try checking the O2 sensor pressure
thanks!

 

BTW: Plugged cats on the H2 are a very common problem.

This happened to me using crappy Shell gas, early into the life of my 07 H2.
And so many codes thrown, that it confused everyone. 2 dealers misdiagnosed the problem. Calling it bad valves and quoting an engine rebuild.

3rd dealer suspected plugged cats immediately (got a smart technician, not a dope like the other ones were), and $2.5K later, it was fixed.
The 4 O2 sensors had to be replaced, as they are near impossible to remove without damage.
Could have done it much cheaper using aftermarket parts, but wanted to keep the vehicle stock with OEM parts.

Note: if you pull the O2 sensors, just be aware that you may need to replace them afterwards if they break. Let them soak in Kroil or something overhnight before you attempt removal.

Switched to Chevron gas. No problems since.

 

Hi finall,
sorry I didn't see your full post, I'm still getting the hang of the posting in forums thing. I will try your recommendation with the cats. I am mind boggled as to why there would be so many codes? the engine seems to run fine when its sat there idling, but when you start to drive at highway speeds thats when the engine stalls and won't start back up until it cools. I'll check for misfires again
Thanks for your help
Steve