Troubleshooting No Trailer Message for Brake Controller on 2006 Ford F-350 Super Duty

Updated 04/14/2020 | Published 04/11/2020

Question:

my 2006 Ford F-350 was giving me an alert to check my trailer. problem was i was not connected to the trailer. every time i applied the brake the warning tone would sound and the message would read check trailer and tbc fault. i ask a mechanic what might be the problem, he said i needed an new controller that mine had gone bad. so i ordered a brand new one that was not cheap it arrived and i put it in only to find the same problem. i have no idea what to do now. any help would be appreciated guys. that warning tone and message are about to wear me out!!!!!

asked by: Robert S

Expert Reply:

If the brake controller on your 2006 Ford F-350 is saying that the trailer is not connected then it sounds like you have an open circuit on your brake circuit. If you check out the attachment from the instructions for the Prodigy P3 # 90195 brake controller (on of our most popular) you can see that the probable cause for something like this includes:

1 - Trailer not connected to tow vehicle
2 - Trailer connected with open circuit on brake line
3 - Trailer connector disconnected or corroded
4 - Loss of trailer brake magnet ground

So what I recommend doing is checking your truck and trailer 7-Way for any dirt, debris, or corrosion and then moving on to all of your wiring and grounds for the brake circuit. Make sure none of your wiring is damaged and that all of your grounds are secured to a clean, bare-metal surface. Since you're getting the same alert with 2 different brake controllers (and one of them being brand new) I would be surprised if it isn't the wiring as this is a very common thing.

expert reply by: Jon G