Have read all the threads I could find regarding TBC fault (and many more than once) and still haven't been able to resolve. Have been having this issue for 5+ years and always just hit reset and go on but now wanting to sell the truck and need to get it fixed prior to sale. Hate to take it to Ford an hour away and pay to have tested but will likely have to. Wanted to try one last ditch effort to see if anyone had thoughts or has had similar issues to mine and resolved.

2005 Ford F250 Super duty
TBC Fault comes up at startup (with or without trailer attached) and I can clear it with a reset and it doesn't come back until next startup.

With trailer hooked up everything works as normal, except will intermittently flash trailer disconnected at random (which seems to be more likely when hit a bump suggesting loose trailer plug connection). All trailer lights work, trailer brakes work when I manually slide TBC lever and when push brake pedal, bar graph works when pressing brake pedal and increases harder you push the brake suggesting brake pressure transducer is good.

Have taken apart the TBC with no bad solder joints visible and have tried a brand new TBC controller, same issues

Have taken apart the 7 pin and no corrosion found but went ahead and cleaned all contacts and applied dielectric grease, same issues.

Have tried with 7 pin disconnected and still get TBC fault.

No dual 7 pin in the bed.

I'm at my wits end, Any thoughts?

 

Subscribed. I have the exact same issue. Was told by a shop to replace the TBC with another Ford one. Simple plug and play, but haven't tried that yet. Searching the forum to see if anyone had it resolved before buying a new one and still getting the same thing.

 

Just a thought... Although you have already tried something similar..

I was told to use a silicone spray right in the connector.. Sure thing... Worked great...

 

I was told the same thing so bought a brand new Ford OEM controller and same issue still. Definitely aggravating trying to diagnose the issue.

 

Have you gone futher into the wiring from the 7 pin connector? I think it splits at a connection in front of the spare tire. Maybe that is loose or dirty?

 

 

 

As an update, it wound up being the brake hydraulic pressure transducer which is the sensor on the bottom of master cylinder closest to firewall. I wound up getting an aftermarket one from the local parts store (listed as brake pressure sensor for ~$90 compared to $120+ for the Ford part that had to be ordered; I also found some online for $18 - $35 but was scared to try those) and just plugged the new one in without installing and the TBC Fault went away. I then went ahead and installed it and I'm good to go. Nice to be able to start the truck and not have to press the reset button to clear the TBC Fault message every time I start it.

For others having the TBC Fault issue and depending on symptoms, might be worthwhile to get a brake pressure sensor and just plug it in without installing to see if that is the issue. If it doesn't fix it, then you may be able to return the sensor given it technically hasn't been installed (at least won't have brake fluid on it).

Now if I can just sell the brand new OEM brake controller I purchased to recoup some of my cost. Trying to be cheap and avoid paying the dealer to diagnose, isn't always cheap in the end.....