OK we have been working on this for a little while now and it is puzzling.

We are getting an intermittent yaw sensor code. We pulled the seat and found lots of moisture so we are drying that out. We pulled the sensor and cleaned everything and let it dry out for a while.

Now we can drive it and the associated messages and lights will come on for a few miles and then all go off for a few miles.

We noticed this morning that going down a long downhill with the brakes on made it come on and it stayed on for a couple of miles until it got home. . Just went to move it and no warning lights.

Had it scanned Monday and the only code left is C0186

 

Replace the sensor they dont like getting wet

 

X2 Correct the reason for the moisture ASAP..... Sunroof?

 

Yes the sunroof drains were clogged and we corrected that and drilled out the slits. They work now.

The intermittent nature leads me to believe that the sensor is the problem.

 

After receiving several inches of rain last night with the Hummer pointed uphill we discovered that the rear drains were blocked as well.

Back to carpet trying with thunderstorms predicted every day

I think the left rear drain is the one that floods the yaw sensor.

 

well at least you found the main issue so that is good. even though it sucks.

 

I'm having the same issues, when you first where having the problem the hummer wouldn't start? And was your gear shifter stuck in park, because mine is and idk if the happens with a faulty yaw sensor?

Welcome to HF.

I got rid of your other post in the WRONG section (HF Help & Suggestion section has NOTHING to do with any vehicle, and is only for questions on how to use the forums.... even says so in a sticky at the top). You tacked your question on the first Yaw Sensor thread you stumbled on and your assumption that this was going to be helpful was wrong.

Here are some suggestions:
1) a Yaw Sensor issue is NOT going to stop your vehicle from starting;
2) you need to immediately fix your plugged sunroof drains as you by now have repeatedly soaked your BCM and likely need a replacement with programming;
3) not being able to move the shifter confirms a bad BCM; and,
4) start a new thread, indicate your year, model (H3s come in 4 models), miles, any recent work done before the problem began, a description of the symptoms you are seeing, and post all codes found when scanned.

There are some good threads here on how to fix a clogged sunroof drains, and vids on the web. Do NOT use compressed air, it does more damage than it can ever fix.

Good luck.