Trailer Fault / Check Trailer Errors on Brake Controller

On our last trip from Gordonsville, VA to Kiptopeke State park on the Eastern Shore of VA, I started to have problems with my built in Brake controller on my F350. Trailer Fault / Check Trailer errors would come up on the brake controller panel and when it was the fault, I would loose the brakes for a few seconds. This made braking lots of fun, so I made sure I kept a safe distance from the cars in front of me.

If you remember, I had this problem before and really never had a solution to it or why it just stopped. I checked all the wires under the camper along with cleaning the 7 pin connector with steal wool wrapped around a drill bit, but still no good.

After reading on the Ford diesel forum, I found that there is a TSB out for the 2008 Fords that water gets into the back of the 7 pin connector and shorts out the connections.

Well, I remembered it had rained 2 times before we left Gordonsville, VA.

I pulled mine apart, the wire harness terminates on a female connector, and the 7 pin male is plugged into this female connector. When I separated the 2, water almost ran out. The connectors were all green with corrosion. I blew all the water our with air and let it dry for a few hours. Cleaned all the contacts with a dremel brush and coated it all with dielectric grease. Put it back together and connected up to the CAT just to make sure everything worked OK. Then put some silicone sealer onto the back of the plug to seal it off. Seems that the back has no sealer, each wire has a rubber grommet to stop water from entering, and mine must leak.

So, if any of you have trailer faults or check trailer errors, check your connectors on the back of the 7 pin plug. I don't even use this plug, cause I have 1 mounted in the post inside the bed, but I think(or hope) the corrosion was causing the errors.

Thanks for the heads up on that one.

Thanks! I've had this problem for the last 3 years. I took
it into the dealer and they said it'd be $500 to replace the controller
and charged me about $100 for the diagnosis that it was faulting.
I said forget swapping it but shut off the visual alarm because it
covered up my mileage display. They took the fuse out and
completely shut it off, morons! Then they didn't bother to give
my the fuse back! I had to install a spare, they got a really
nasty email from me.

I'll pull it apart and see if that fixes it.

As an aside...mine gives me faults without the WC connected.

Cardinal_Bill wrote:
As an aside...mine gives me faults without the WC connected.

Bill,
Definitely the 7 pin plug, thats what everyone on www.thedieselstop.com was complaining about, getting the errors without the trailer plugged in. Try separating the connectors and see if yours is all corroded like mine was.

Read here

Well, after pulling my 7 pin connector on the truck all apart and cleaning it up(see above), I connected up today to take the CAT to get the hubs repacked and all the way down I-95 all I heard was DING DING DING!!! TRAILER FAULT, CHECK TRAILER, again and again..

So while we were in the shop I had the mechanic cut the original 7 pin connector (on the CAT side) off and replace it.

NOT A PEEP ALL THE WAY HOME!!!

Its finally fixed, I hope.....

Good catch Tom

I think that this was an important post for all of us that use the trailer harness that's built into the bumper. Gonna take mine apart tomorrow and take a look.

A BIG THANK YOU TO DA' MAN.