NHTSA Complaint #11589523 — 2024 GMC SIERRA 3500

The in cab brake controller does not work with electric over hydraulic trailer brakes. In my research to diagnose and fix the problem I find out GMC has known about this for years and has done nothing to correct. I pulled code C1114 and GMC issued a bulletin for part number (K58-036-00) which I purchased and still did not correct this issue. In short there are many 3500 trucks out there running with no trailer brakes. Here is the worst of this problem. If brakes are tested at a stop they appear to work perfectly however once driving this is when the error code is delivered to the truck so the brakes work at a stop when not needed and do not work under driving when they are needed. GMC has ignored this for years and after spending more of my hard earned money for a fix that did not fix the problem. Below I had to choose a date however this has been an issue since first purchase December 5th 2023 to present.