I wanted to share a fix I performed on my 2008 Buick Lucerne. The Stabilitrak light was on and the DIC displayed "Service Stabilitrak."
Diagnosis: Scan tool showed code C0701 - Steering wheel position sensor.
When I first started the car, Stabiltrak light went out, but as soon as I turned the steering wheel, the light would come on.
I unplugged the Steering wheel position sensor, checked reference voltage for 5 volts (gray wire) and ground for less than 1 ohm (orange/black wire) both were good.
Connected my voltmeter (my scan tool did not have the capability to do this) to each output wire (lt green & lt blue) with connector plugged in and watched the voltage change as the steering wheel was turned lock to lock, all seemed good.
When I plugged the harness back into the sensor, I noticed it felt rather loose; I also noticed it would move as the steering wheel was turned. I held the plug into the SWPS as firmly as I could and turned the wheel again, fault indicator light did not come on.
I found the TSB about putting a zip-tie around the wires to keep them from moving, but it did not help. Obviously, this was an issue on these components.
I ordered a new plug (pigtail) but it fit just as loose as the old one, so I did not install it.
Instead, I drilled a small hole through the red wire lock that is supposed to keep the wires in their place. I ran a length of flexible wire through the hole, around the column, and twisted the ends together with a pliers.
The plug is now tight and does not move. Started the car, turned the steering wheel, no fault indicator light, no DIC message. I have driven the car several miles, made several turns, even did some slalom turns in a parking lot and so far no failure.
So, before you spend big money and/or time replacing the sensor, try this trick first. Cost $0.00

Cool, thanks for the write-up!

As these vehicles age and the odd parts start failing, this kinds of fixes will be more and more important.