NHTSA Complaint #11624149 — 2023 TOYOTA SEQUOIA HYBRID

The ECU in my Sequoia is incorrectly programmed when towing a trailer. I have a 6,000# dual axle electric brake travel trailer that I use my Sequoia to tow with. I set up the trailer specifications in the vehicle computer per the Toyota owner's manual and set the trailer gain per the Toyota owner's manual. The problem I experience is when the gain is set this way the trailer brakes lock-up under moderate braking. To remedy the trailer brakes locking up, I reduce the gain. The problem is, in order to stop the trailer brakes from locking up under moderate to heavy braking, I have to reduce the gain to the point the trailer brakes are effectively not operating. I have already brought the vehicle and trailer to a Toyota dealership, and they were able to reproduce the issue I am experiencing with the brakes. However, Toyota has closed my case with no remedy. I never experienced this issue with the previous vehicle (a 2015 Toyota Tundra) I used to tow this same travel trailer with. I believe the ECU is incorrectly programmed causing a different voltage output being provided to the trailer when 1) the brake pedal is depressed; vs. 2) when the trailer brake controller slider is operated (to set trailer gain).