I have an '08 F350. I keep getting a beep and the message that I have "faulty trailer wiring" WITH NO TRAILER CONNECTED. I can clear this message with the reset button but about 50% of the time it will come on again the next time I start the truck. Twice I have taken this problem to one of the largest dealers in Minneapolis but they cannot figure it out. What is especially maddening is they don't even know what the "fault" is that the computer is sensing so they are just poking around like blind men. Does anyone know anything about this? - Does Ford Motor Company even know any thing about this?

 

Have them check the connector and harness for water and corrosion. Mine's been replaced once and it's doing it again so I guess they need to replace everything again.
jr

 

JR,
Thanks for your reply. Are you referring to replacement of the trailer connector at the rear of the truck or to some other connector in the wiring harness?
TT

 

Both, they replace the connector plug and the wiring pigtail. There is a TSB on this, (can't recall the number).
If your dealer is any good they already know about this issue.
jr

 

JR
Thanks, I'll be contacting my dealer (again) today.
TT

 

Hello I bought a tow command kit from ford last year. I have not put it on they yet because i need more direction than the 2 papers that ford gives. I also bought the upfitter switches. Now i'm going to buy the harness and Central Junction Box. My question is with the kit a new master cylinder came with it with a extra plug and i can not find the plug new to the fire wall. If anyone knows please reply. thanks i have a 05 f250 xlt

 

Mile was beeping, telling me the trailer was disconnected. (It was partially right - my RV was still 3 hours away in Wisconsin!)

Anyway, the dealer replaced mine.

 

Installed both in mine over 1 year ago. My truck had the wire/plug floating around the old master cylinder - away from the fire wall. It was hanging down about 1 foot lower then the master cylinder & facing towards the ground. It was between the engine and the master cylinder. It had a cap over the plug.

 

I had the TBC fault on my 06 and it was the entire module. worked great till I traded for my 08.

 

thanks stevenn1 you have been alot of help and thanks to all the people on here. you have saved me alot of time and money

 

Interesting thread.

I have a power drain (.5 amps) that I can not isolate. If I pull the "cluster" fuse, the drain goes away so I paid for a new cluster and still have the problem. However, now with the new "updated" as the parts department told me, I get the TBC fault. I put my old cluster in and no fault.

Two things, maybe this is pointing to my power draw. And second, maybe it is just a cluster glitch. Mine came on with no trailer hooked up and I never got it with the old cluster. Now I'm going to check the connector at the master cylinder... Man this is driving me nuts!!!

 

Damn Im having the same problem but Ford tells me its nota TSB or anything. For the last 2 months everytime I start the truck it beeps TBC fault. What can I do to fix this? I don't want to take it to the dealer if I can avoid it. Where is this diode located?

 

Anybody know where this diode is located. I had mine at the Ford dealer and was told it needed a new brake controller. It was going to be a $400 bill so I told them that I'd think about it. I'd like to try and fix before I buy a new brake box.

 

The TBC is a plug and play type device. If it is bad, just unhook and get a new one to fit in the slot.

Of Course don't forget to uplug from the wiring harness

 

Seems like a lot of folks having this problem. I'm having the problem as well with my 2006 F250. TBC Fault at start-up. Sometimes it resets, sometimes it comes back immediately after reset. Seems that going over bumps sometimes causes it to trip. It's terribly annoying hearing that bell every time I go down the road.

I don't want to take it to the dealer. I never pull a trailer with electric brakes. Can I just remove a fuse, or will that affect something else in the brake system?