Trailer Brake Issue - F150

[TheBigPig]

Took out the camper over the weekend for the first time and realized I have an issue with the tow brake in my truck.

I have a 2015 F-150 2.7L Ecoboost. I installed an OEM trailer brake myself and then had the dealership flash the computer to recognize the brake. The display on the F-150 shows the gain setting along with an output reading. As you apply pressure to the brake, the output gauge should rise.

I connected the camper for the first time and while trying to adjust my brake setting, I realized that adjusting the gain was not making any difference to the braking and that the output gauge was not increasing as I pressed on the brakes.

The trailer brake does engage and the output gauge does increase when I squeeze the brake controller with my fingers to engage it manually. When I press on the brake with my foot, nothing.

So far I have checked the contacts on the trailer plug and the truck, and the fuses in the truck. Does anyone have any advice on what else to check here? I plan on calling the dealer who programmed the brake controller as well, but wondered if anyone else had this issue.

[JRTJH]

Squeezing the lever applies the brakes "manually" while pressing the brake pedal uses the vehicles "accelerometers and speed sensors" to properly manage the braking force...

In other words, if the vehicle isn't moving, the brake controller will not apply voltage to the trailer brakes.

So, the information you "left out of your post" is: When you press on the TV brake pedal, is the truck moving at a speed greater than 5MPH? If not, you won't see a voltage on the 7 pin connector and you won't activate the trailer brakes (if it were jacked up and you were turning a trailer wheel).

[TheBigPig]

JRTJH,

Thanks for the response. I took the camper out over the weekend and got it up to at least 55-60 mph on the highway and went down some decently steep hills and was getting no reading on the output gauge. I had the gain up and down during the trip with no results. Also, I am under the impression that the output gauge should be lighting up when I press on the brake with the trailer connected even when I am stopped (based on youtube videos).

Also, When I bought the camper, the RV dealer put an aftermarket brake controller in my truck, which was definitely working as I was able to get the camper tires to skid. I decided to install an OEM TBC because I didn't like the look of the aftermarket product attached to my dash and I wanted the Ford tow display.

[JRTJH]

If you "took out the old brake controller and installed an OEM controller, did the person who installed the original aftermarket controller "modify" the wiring harness to tie in the aftermarket controller? If so, did you "unmodify" the wiring to get it back to the OEM configuration? I know it's a "far fetched what-if" but .....

[TheBigPig]

No, a wiring harness was used to convert the wiring to the aftermarket product. I took off the harness, plugged in the OEM TBC, and had the dealer program the OEM TBC so the truck would recognize it. I think I'm going to call the dealer to see if they didn't program it completely.

[JRTJH]

Yep, if the trailer brakes were working with the aftermarket controller and nothing has changed on the trailer or the 7 pin connector, then it's apparently something with the OEM controller or the way way the dealership "flashed the computer"....

On my 2010 F150, when I installed the OEM controller, the dealer flashed it and everything worked as planned. I had not installed a brake controller previously, so I had no wiring to reconfigure....

I agree, time to call the dealership. They "should have" a means to verify the 7 pin connector output on your truck. I'd suppose that they "should have done that as a part of the computer reflash"...

[NH_Bulldog]

My 2015 F150 came with the brake controller factory installed. As I understand it (it is in the owners manual starting on page 266), the brake controller applies braking power to the trailer that equals brake pedal pressure. If everything is working correctly you would not necessarily see the power graph display increase to any great degree. The Gain setting is the “extra” power (+) applied to put more stopping power to the trailer or less (-) depending on your specific set-up.

It is not at all like an aftermarket brake controller, especially if you had a timed brake controller as opposed to an inertial type. To me, the OEM brake controller works seamlessly and virtually unnoticed, without any tug or pull from the trailer to let you know it’s there, but it does work.

[TheBigPig]

NH,

I understand that the power to the trailer brake will fluctuate. Problem is, my gauge is not showing any output at all to the trailer brake when I press on the brake. It is only showing output when I squeeze the brake with my hand. Since you have a 2015 F150, can you please confirm that the Output bars light up when you press on the brake? It is my understanding that I should be seeing some output on the gauge. See the photo attached to see what gauge I'm talking about.

Thanks.

[NH_Bulldog]

When I first got the trailer I had the same initial concern, I expected to see that graph light up like a Christmas tree......it doesn’t. Under normal braking I almost never see any of the graph light up. I am in Tow Mode and that uses the engine/transmission to contribute to braking so the brake controller rarely has to apply a disproportionately higher amount of power to the trailer (which would be shown as the bar graph lighting up).

Remember, the truck and trailer are working as one unit with the factory brake controller, unlike with an aftermarket one where two separate units are trying their best to get along but really have no way to talk to each other. An aftermarket timer brake controller (the least expensive) uses an initial surge of power applied to the trailer and then slowly reduces the power over a set period of time. This often results in a tugging or jerking of the trailer on the truck because there is a disproportionate amount of braking applied to the trailer....you KNOW the trailer brakes are working. A proportional brake controller uses inertial gyros in the unit (Prodigy brand is one), and these are much more expensive, but apply braking to the trailer based on your speed and is reacting to the braking from the truck. When properly tuned, it works excellent, but you still know the trailer is braking.

On to more of your concern; First, assuming that the trailer brakes are operational and properly adjusted. At a stop or moving VERY slow, manually activate the brake controller. The graph should light up completely and your trailer wheels should lock up. That means the controller is working. Now, at a stop with your truck in gear, your foot on the brake and gain set to 10, slightly lift your foot of the brake and before you start to move, press hard on the pedal and watch the graph. Try it with varying degrees of force and pressure. You should a few of the lights show, but they only appear for a second, they do not stay lit.

Last option is to take your truck and trailer to the dealer to have them check the system.

[skids]

Referring to post #8, with my 2014 F150 3.5L SCREW 4x4 with OEM brake controller, I am pretty sure that when at a stop, if I mash the brakes, it shows gain. The harder I press, the more “output” shows. One thing I noticed is that the trailer brakes work much better after being warmed up. This whole business of not activating the trailer brakes when going less than 5 mph is criminal if true. I have a steep gravel driveway and so far, the trailer has not “pushed” my truck while going less than 5mph down that hill.

[TheBigPig]

NH,

Thanks for all that info. I guess the hangup I have is that my brother has a 2019 F-150 with the same towing display. When he is towing his camper, he sees the output gauge light up every time he uses the brakes. While researching the issue I came across this youtube video. If you start at 1:35, you'll see that just having his foot on his brakes lights up the output. Not sure the year of the truck in the video, however.

https://www.youtube.com/watch?v=IYJvRZRHBk4

Also, I would assume I should be able to set the gain up too high at some point and get the camper to skid. This is not happening. I'm pulling a relatively light camper (dry weight 4730), so I would think I'd be able to get it to skid.

No matter how hard I smash on those brakes, I get no lights on that output gauge.

[JRTJH]

Originally Posted by skids

Referring to post #8, with my 2014 F150 3.5L SCREW 4x4 with OEM brake controller, I am pretty sure that when at a stop, if I mash the brakes, it shows gain. The harder I press, the more “output” shows. One thing I noticed is that the trailer brakes work much better after being warmed up. This whole business of not activating the trailer brakes when going less than 5 mph is criminal if true. I have a steep gravel driveway and so far, the trailer has not “pushed” my truck while going less than 5mph down that hill.

Actually, it's not 5MPH, the brake control limits output below 11MPH. It's in your owner's manual, page 205:

"The trailer brake controller is equipped with a feature that reduces output at vehicle speeds below 11 mph (18 m/h) so trailer and vehicle braking is not jerky or harsh. This feature is only available when applying the brakes using your vehicle's brake pedal, not the controller."

Applying tow vehicle brakes with the manual lever on the brake controller "should still apply braking power to the trailer" (and that's where I think the 5MPH limit is applied through the vehicle accelerometers when using the lever and why you can't read a brake signal output on the 7 pin connector) but pressing on the brake pedal when the tow vehicle speed is below 11 MPH will apply little, if any braking power to the trailer brakes. It's set up that way to prevent the "jerking and chucking" in "stop and go city traffic conditons"....

Also, if you "read between the lines" Ford "infers without actually stating" that there is no "anti-sway capacity" that uses the trailer brakes. They "allude" that the way the "trailer anti-sway system" works is by reducing engine power on the tow vehicle and using the tow vehicle anti-skid feature to prevent/help reduce trailer sway... When you "think outside the box" there is ONE wire from the tow vehicle to the trailer brakes. There's no way the tow vehicle can apply braking power to any specific trailer wheel or even to any specific side of the trailer. And, thinking further, the way "electric magnet brakes work" there's no way to apply a "modulating current to prevent wheel lockup and loss of traction"... That system works on the tow vehicle brakes (and you can feel it in the pedal as it pulses the braking effort)... Electro-mechanical brakes on the trailer are not capable of that same "pulsing action", they just don't respond quick enough to expand/retract from the hub surface fast enough to accomplish the "anti-skid action"... That's why there's the note in the Ford owner's manual that says not to use the manual lever on the brake control to stop trailer sway. The "old custom of using the lever" that we've all "learned to do with separate brake controllers" can, with the Ford OEM controller, set up a wheel lock condition, cause the trailer to lose traction and make sway "uncontrollable" with the computer program in the tow vehicle's anti-skid system.....

Ain't technology "wunnerful" <sigh>

[markcee]

Originally Posted by TheBigPig

NH,

Thanks for all that info. I guess the hangup I have is that my brother has a 2019 F-150 with the same towing display. When he is towing his camper, he sees the output gauge light up every time he uses the brakes. While researching the issue I came across this youtube video. If you start at 1:35, you'll see that just having his foot on his brakes lights up the output. Not sure the year of the truck in the video, however.

Also, I would assume I should be able to set the gain up too high at some point and get the camper to skid. This is not happening. I'm pulling a relatively light camper (dry weight 4730), so I would think I'd be able to get it to skid.

No matter how hard I smash on those brakes, I get no lights on that output gauge.

I can see that as a hangup as well. '19 F150 and '19 F350, both with Ford ITBC and there is a registered output every time you apply the brakes. It may be only 1 or 2 bars, but you WILL have an output.....at least I do.

Suggest posting your issue in the Towing/Hauling/Plowing section of f150forum.com for further input.

[skids]

Here is one for you. I had a 2016 Jayco RB190 with a single axle. Dexter said that the braking system is incapable of wheel lock-up (I think on asphalt). That was a 3500 axle/ max load.

[TheBigPig]

Markcee,

Thanks, I do have an ongoing post on f150 forums as well. The dealer is taking a look at the truck tomorrow, I'm hoping it's a computer issue that they can easily adjust/fix.

It is my belief that after you set the gain per the Ford manual, that should be the baseline setting, giving you max output to the trailer brakes when the brake pedal is to the floor. Regardless of that setting, the output when you press the foot pedal should register some output, depending on how hard you are pressing on it.

[flybouy]

Originally Posted by TheBigPig

Markcee,

Thanks, I do have an ongoing post on f150 forums as well. The dealer is taking a look at the truck tomorrow, I'm hoping it's a computer issue that they can easily adjust/fix.

It is my belief that after you set the gain per the Ford manual, that should be the baseline setting, giving you max output to the trailer brakes when the brake pedal is to the floor. Regardless of that setting, the output when you press the foot pedal should register some output, depending on how hard you are pressing on it.

It's not directly correlated to brake pedal pressure. There are several inputs tyhat "adjust" the output including speed and inertia. While my trucks are much oldrer the IBC will show a minot voltage output while the truck is stopped. It doesn't matter how much pressure is applied to the brake pedal while at rest the reading is the same. If I take my foot off the brake while stoopped and apply it again it will breifly indicate a higher voltage then immediatly reduce back down to a min. They typically don't lock up the trailer wheels nor do you want them to. Skidding rubber on the road = loss of control, this is the reason for ABS on your truck or car.

Simply set the baseline, drive cautiously until you get the controller fine tuned where braking with the trailer attached should roughly approximate driving the truck unhitched. If you cannot reach that adjustment (I.e. either truck doing all the braking or the trailer doing all the brakeing) then either the brake controller or the trailer brakes have an issue.

[TheBigPig]

Just picked up a 12v light up circuit tester.

Left turn, right turn, brake lights, running light contacts all show voltage.

When the TBC controller was squeezed by hand, voltage was detected on the electric brake contact and the tester lit up.

When the brakes were stepped on, no Voltage was detected on the electric brake contact.

The Positive terminal, which I think is Aux Power to charge my battery while towing shows no voltage detected.

Negative terminal shows no voltage (expected).

So I think that verifies my concerns. Thanks to everyone who tried to help, I'll let you know what the dealer says.

[jasin1]

Originally Posted by TheBigPig

Just picked up a 12v light up circuit tester.

Left turn, right turn, brake lights, running light contacts all show voltage.

When the TBC controller was squeezed by hand, voltage was detected on the electric brake contact and the tester lit up.

When the brakes were stepped on, no Voltage was detected on the electric brake contact.

The Positive terminal, which I think is Aux Power to charge my battery while towing shows no voltage detected.

Negative terminal shows no voltage (expected).

So I think that verifies my concerns. Thanks to everyone who tried to help, I'll let you know what the dealer says.

I think there is a relay that the computer uses and a separate fuse for the controller power.. check to see if the relay is in place. If the fuse is bad ther will be no power to the controller but the relay could be bad or missing and the controller would still power up

[bbells]

Many newer trucks have separate fuses for the trailer connector. Check them. My Lincoln Navigator was set up that way. Crummy tow vehicle, though.

[hazmat456]

Originally Posted by JRTJH

Actually, it's not 5MPH, the brake control limits output below 11MPH. It's in your owner's manual, page 205:

"The trailer brake controller is equipped with a feature that reduces output at vehicle speeds below 11 mph (18 m/h) so trailer and vehicle braking is not jerky or harsh. This feature is only available when applying the brakes using your vehicle's brake pedal, not the controller."

I have a 16 F250 and my manual says nothing of the sort. page 205 is about towing the vehicle. The section about trailer towing is before that. What I can tell you is that my trailer brakes can lock up and skid to a complete stop, I see no evidence of the brake controller lowering the voltage.

I would suggest to the OP that the settings my be for electric over hydraulic, or something other than 2 axle electric.