Question

How to fix the code U0121 on a 2008 Chevrolet Silverado 5.3L?

Answer 1

Hi there

This could be an issue with the brake control module or the wiring harness for the module. There are several bulletins for this issue through GM. Here is some more info on the code for you.

U0121 CHEVROLET - Lost Communication With Electronic Brake Control Module
Read more: https://www.autocodes.com/u0121_chevrolet.html