ABS brake control module location on 2001 GMC Sierra 2500 HD

My brake light and ABS light keep coming on intermitantly, not all the time. I was told it is the module and needs to be replaced. Where is it located on my truck?

3 answers 1 comment
under the truck on or above the frame rail

why are you replacing it?? what was the code and did a shop do a diag??

Roy.
Yes, Les Scwab checked the code and it showed ABS Control Module needs replacing.
We need to know where it is located
Where is this sensor located