My F350 6.7 diesel 2011 35000 miles experienced erratic braking on my last trip.
When I applied the brakes it felt like the trailer brakes would come on and off full , repeatedly which really jerked the truck. I have been testing at the trailer plug with volt meter on the pin, the gain is set to 10 and I get approx 12.5 volts when I use the integrated slide controller in the truck and as I change the gain the voltage changes, but when I step on the brake it takes a few seconds to register voltage and only gets about 6.5 volts no matter where i set the gain. I also have a plug in the bed and both plugs register the same.

Any suggestions or help would be much appreciated. Graeme

 

Graeme, In order to test the Ford IBC correctly, you need to be moving. At speeds less that 10 or so mph, brake output is limited per the manual. Slider gives you full output. There is a tester that is nothing more than wheel magnets in a box with a long 7-way plug and a meter connected to it so that you can see the output while moving.

To help isolate the problem, you could tow someone else's trailer to verify your truck vs your trailer is the problem.

Did you get any trailer fault messages or other codes?

 

I doubt that you would need anywhere near a 10 setting with properly working brakes. My guess is that you have an intermittent connection at the plug or elsewhere on the trailer.

 

Make sure you have the setting correct. Elect or elect/hyd

 

A trailer wiring fault showed up a couple of times but does not coincide with the eratic braking
The 5th wheel is only 2 years old and I have towed it 7000 miles with good brake operation.It seems like when I step on the brake pedal It goes to full output. When I use the manual slider it seems to work ok. I have switched plug from bumper to in the bed and no difference. I have never seen a setting for elect or Hyd. maybe not available on 2011.

 

Not on 2011, if I remember right.

 

My 2011 KR has the option for either elect or elect/hyd.
mine is done on the instrument cluster

 

I connected my voltmeter to the brake wires coming from the 5th wheel at the junction box on the trailer. Using the slide switch with the gain set to max 10 the voltage increases gradually as I slide the switch to battery voltage. This seems to be fine. When I step on the brake pedal, ( truck running) I get no voltage at 5th wheel, but sometimes I get 5.5 volts. As I am connected to the same wire, (it is the only one coming from the truck) I feel the problem is between the integrated brake controller and the brake pedal. Any thoughts?:

 

I have searched for the elec/hyd option. not there on my lariat. I had been driving for 3 day straight and all was working well when my problem started so something happened that I can not find yet,

 

I had this same exact problem and it turned out to be one of the brake magnet wires shorting out against the hub on my brand new 5th wheel. Pull your brake hubs on the trailer and make sure all your magnet wires are still in their clips. I also had the intermittent trailer wiring fault pop up. I also thought it was a problem with the brake controller because I wasn't seeing the voltage I wanted to see when applying the brakes, but as mentioned above, the truck has to be moving in order to properly test Ford's brake controller.

 

Thanks for the reply. That will be my next step. If the truck is stopped I think there should still be voltage at the brakes because when I am stopped at a stop lite arn't the trailer brakes on also? I will keep you posted. can't work on it today because I have to go fishing.

 

SUCCESS. Thankyou tmilicia. and all others that replied. tmilicia, your reply was rite on, I pulled all of the wheels and drums and of course on the last one that I pulled, the wires were broken off the magnet and I guess they just started to short out .All looked brand new in there so I guess that brake never worked. It will be a while before I get it together to test because I have to order a magnet.If I don't reply in a couple of weeks all is good.

 

Glad you got it solved. Mine was the last wheel I checked too and I have 6. Lol. It's happened twice now, so I keep an extra magnet in the toolbox, just in case. I can change a magnet in about 15 minutes now.

 

I'm having the same brake controller problem on my month-old 2019 F-250 that others are describing: can't send sufficient braking power to the trailer, even with the manual control; electric-over-hydraulic setting is better but still not sufficient (trailer is not EOH, setting just works better); dealer claims the controller is up to patch level and passes all their tests; trailer brakes were working fine last month with our traded-in F-150.

Trailer is less than a year old, truck less than a month old. Age and connector corrosion should not be issues.

I'm going to have an independent mechanic pull the trailer wheels and verify that none of the magnet connections coincidentally snapped or shorted while we were out buying the new truck. If he finds nothing, I would like to bypass the integrated controller entirely and use something like a Curt 51180 until (hopefully) Ford gets its scat together and changes their controller firmware to make it work at least as well as an $80 aftermarket knee-scraper.

Here's my question: I've heard that certain circuits on the rear 7-pin connector are not activated unless the vehicle is in tow/haul, and/or that the integrated controller may interfere with the signals on certain other circuits. How do I have to configure the integrated controls to take them out of contention, and make the 7-pin connector act exactly like it would on a "dumb" vehicle?

 

On the 2011-2016, the tow/haul switch does not affect the trailer brake controller. The tow/haul changes the shift patterns of the transmission to help prevent the gear "seeking" when at low speed such as in town or in the mountains. I would assume the same is true of the 2017-2019 trailer brake controller and tow/haul mode.

I would think the "sensing of the trailer" does affect whether the trailer brake controller sends a brake action signal to the 7 pin plug. When the TBC senses a trailer, it would activate the braking action in accordanace with the gain set on the TBC. The TBC should be like the aftermarket controllers and "gradually" apply the trailer brakes.

I am not sure i would want to make the 7 pin plug a dumb plug unless you are sure the trailer is not the problem and/or the truck TBC is not at fault. The dealer should have a method to test it. The attached pdf's are from the 2016 Ford Workshop DVD. 2019 might be similar.