Warning light came on the dash and for the ABS, as well, along with the vehicle going into limp mode.
Later on and after limping it back home, it ran alright except one time with the brakes shuttering for a moment.
And for being OK after except for the dash warning lights still being on.
So for an educated guess after some research, I decided on the cause being a bad sensor that's located under the driver's seat carpet, so I removed it altogether, which made no difference.
Thought I'd check locally and found that the parts stores wanted upwards of $400 for one and for taking about 2 wks after ordering it.
So with dimissing this insanity, I found a ton of these on eBay for around $30, which took less than a week for delivery to my door.
I had previously cut the carpet for making a flap, so the removal and install was much easier than for having to remove the floor trim and possibly the seat itself and depending on just how much twisting, turning and jimmying you like doing. And especailly since it's partially cut already for the seat wiring.
Anyway, all is well now, so do hope this saves some of you a lot of pain, effort and above all, a lot of money for taking it to the dealership. Of the latter, I can't even imagine the shock of seeing the bill.

 

Thanks for sharing.

 

Glad you solved your issue....

Been getting those warnings on and off for years on my 06 H3.

I choose to ignore them. Did not know there was a sensor associated with this alarm.

Can you please share a part #?

 

15096372
Code> C0186 Yaw Rate Sensor Going or Gone Out

 

It's .....Front Driver Side Suspension Yaw Sensor 15096372 FIT For 2006-2010 Hummer H3 H3T ..... but like said, a local parts store with want upwards of $400 and who knows what a GM dealer will charge.
That's why I bought thiis aftermarket product from eBay which most likely is OEM and for coming out of the same Chinese hut, anyway! ...... Click... Yawl sensor

 

Yawl got a Yaw sensor.

 

That's about right for the most part with yaw most likely being the the correct term.
Both having to do with sail boats but with two different meanings.

 

Thanks for those helpful images... hummerz "you da man"

 

So a few end notes having just finished doing this change.

Best to from the back remove 2 ,18 mm bolts and raise up the Subscribedseat so you can access the sensor.

Need a 10 mm type tool to get the 2 nuts holding the sensor.

A sharp utility knife to expose where you will need to work where the factory cuts leave off. ( Look up some you tube videos if you are going to attempt )