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?

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??

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