New Caprice - Discussion forums

I have been working on the abs brake for weeks now have ran new grounds and I have voltage at my abs module have replaced the module twice and I still get the same code U0121 lost communication abs module, please help!!
2012 chevy caprice 6.0 l77

What you would want to do is hook up a scanner and see if you can communicate with the module. If not then would want to look for a break in the data lines. Most likely a bad terminal at one of the connectors is usually what we see,

here is the data wires diagram.
https://www.chiltonlibrary.com/content/ ... 662707.pdf
Is this a new problem? Like was it OK before and it popped up or did the car have the problem when you got it?

Here is a diagnosis on a jeep but similar tasks to do:
Part 1
https://www.youtube.com/watch?v=vMRY8l3ivNE
Part 2
https://www.youtube.com/watch?v=ihLc4d21lBE

Oh and just to clarify. you are programming the ABS module each time you install it correct?