2008 Buick LaCrosse has intermittent traction control off message. Scan tool won’t communicate with the ABS module. Only codes are U1016 (loss of class 2 communication with VCM) which shows up on ABS system, digital radio receiver and radio. The Instrument Panel Cluster has a U1040 (ICC Class 2 Serial Data SOH Fault or lost communication with Electronic brake control module). All 4 wheel bearings checked good. Powers and grounds are good at the brake module. And I tried 2 different used brake modules. Anyone have any ideas?

Those intermittent ones can be a pain. What percentage if the time is it out?
Could be it'* not actually the ABS module that is at fault.

It really isn’t on that often What bothers me more, is that I never can communicate with the brake module. If I can’t communicate, can the ABS be working? With the two “U” codes I only assumed that the brake module was the culprit because of non communication

Can you talk to all the other modules?

I can talk to all of the other modules.When I go into ABS, it just says “no data” for whatever I select. I tried the 2 used modules thinking, what are the odds? I don’t know if I did the right thing, but I sent the original one out to get rebuilt this afternoon. I am stumped.