A few months ago my cruise control started intermittently working. Then my StabiliTrak, Traction Control, and ABS failed. Changing the brake switch didn't solve the problem so the next step was to look at the wheel speed sensors. This may help you because the Silverado, Avalanche, Tahoe, and Suburban are all pretty much the same.
![](https://i.ytimg.com/vi/K--v1K9FYYg/maxresdefault.jpg)