With that code you have a problem with the ABS module located just under drivers door on frame. First check all grounds especially the one on the outside frame looking forward under drivers door. If after cleaning grounds and at least three restarts you still have the code get a used replacement, module and pump from a wrecking yard as a new one cost way too much.. You will still have alight until you drive 5mph or faster to reset computer. Have both a 99&01 silverado 4x4 that had same problems, module was bad.. Good Luck

 

I have a 99 silverado and my abs light came on.i started checking the front end and noticed one of my wheel bearings had some play replaced it and the light went out.

 

So I had the same problem. First check the ground going from the ECM, check for corrosion, dirt, anything that would break ground. If everything is good there, you'll have to pull off the ECM and cut it open (VERY CAREFULLY, TO NOT BREAK THE BOARD OR YOU ARE SCREWED!!!!). Then there are 4min, possibly 6 points on the board that you need to sauter (spelling) back together as a crack has probably formed and is breaking the connection between those points. There is a YouTube video explaining what to do.