ABS/Brake warning lights

[201tahoe]

intermitingly my ABS and Brake warning lights come on in the dash. Sometimes I can drive all day and no lights.... other days they never go off

???????

 

[jey_]

First thing I would check is your brake fluid level. When was the last time you had the brake fluid flushed?

 

[Big Tap]

Like Jey said, it sounds as if it could be something as simple as brake fluid level.
I would also make sure you to check your electronic brake control module if you are hearing a buzzing noise. It probably wouldn't be doing it intermittenly if this was the problem though, but you never know. The noise is similar to that of the fuel pump, but it comes from underneath the SUV on the driver's side, near the driver's seat. GM didn't build them as well as they should have and they have a tendency to go out in their trucks and SUV's.
If this is what it is, you can have them rebuilt by people on Ebay for about $150-$175. They actually are better after that than when they come from the factory since they put better parts inside. This is not something you want to buy from the dealer. It'll cost you $600+ and you still have the same poorly built part going back in.

 

[ronjeremy6]

my 01 did this for the last year that i owned it. final diagnosis was the ECBM. i left it alone, because when you shut off the ignition and turned it back on the lights cleared. sometimes they would come back on the same day or weeks later.