Trailer brake not working

[tderouchie]

I don’t know what to tell you other than I don’t rely on memory, i.e., “I’m sure I [fill in the blank].” I am constantly checking. I don’t move (whether I’m starting my journey or restarting after a fuel up or rest area break) until I’ve interrogated the brake controller directly and verify a connection. I don’t rely on brake “feel.” The specific connection procedure doesn’t seem to matter much in my experience except the step to make sure the brake controller is reporting a connection before moving. Either squeeze the override or push one of the gain buttons and do it before you move.

After I start moving, I constantly check and verify the connection. I look at the backup camera screen (which on Airstreams are tied into the 12v circuit), which I always leave on in transit. I look down at the headlight switch position directly even though the camera should verify that the headlights are in the on position. I push one of the gain buttons on the brake controller to bring up the gray brake controller pop-up. I do all of this repeatedly while driving. Again, I don’t rely on what I thought I did—or felt—when I started moving. I agree it isn’t something we should have to do, but it beats being dead. And I’m not going to just park my rig and complain until Ford fixes it. That will be a long wait.

When my brakes quit, I still have trailer brake lights and still shows my gain settings. It’s as though nothing changes, except the trailer brakes don’t engage.

For those of you who have gone to a Ford dealer, do you know if you all have the code for “lost communication between BCMC and TRM”?

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[JEB]

When my brakes quit, I still have trailer brake lights and still shows my gain settings. It’s as though nothing changes, except the trailer brakes don’t engage.

Thank’s for posting this because it helps illustrate something important—what does and does not indicate a proper trailer brake connection. Trailer brake lights are NOT an indication that the trailer brakes are communicating with the controller. Brake lights are on a different pin on a different circuit. Just being able to see your brake gain setting also is NOT and indicator that your brakes are communicating with the controller. You can do that any time whether you have a trailer connected or not. The only way I know of with this truck that you can actually confirm a proper connection from the cab before setting out is by looking at the gray brake gain pop up, seeing the gain setting and the word GAIN in large font, and seeing no other text. If the trailer brakes are not connected, it will say so in relatively small font below the gain setting that can be easy to miss if you’re only looking quickly.

My concern is that people are looking at the wrong indications of a proper connection and then concluding that they “lost” their connection when they might never have had a solid connection to begin with. It makes diagnosing when the and how the connection was “lost” very difficult.

 

[tderouchie]

Something worth noting is that i have never got the warning saying trailer disconnected.

 

[JEB]

Something worth noting is that i have never got the warning saying trailer disconnected.

So? You wouldn’t. It doesn’t show up automatically. You have to toggle the brake controller manually and read what the gray pop up says. If it says GAIN and nothing else, it’s connected. If it says anything else, it’s not connected. But you have to check. A deliberate action.

 

[chrisp993]

"Absence of Evidence is not Evidence of Absence"

So, updating my experience ... I had the trailer brake controller fail to recognize the trailer and so fail to function on several occasions in July, including confirming working then failing midway through a journey without any stops/restarts etc. just working, then not working. I've used my trailer (2019 ATC Enclosed Car Hauler) several times and ~ 1,000 miles in August and hadn't had any problems - I've tried multiple suggestions from this thread, headlights switch etc. but could not repeat the issue. Until ... it happened again ?

After spending this past weekend at the track, I made sure the headlights were ON, hooked up my trailer and got nothing ... no trailer attached according to the trailer brake controller. I tried multiple combos, headlight switch OFF, ON and AUTO, letting the car perform a complete shutdown before restarting, unplugging, plugging the physical trailer plug etc. and could not get the trailer brakes to function. So, frustrated, I set off home, headlights on AUTO, stopped after about an hour for gas and a bite to eat and 20 mins later upon returning to truck, started back up, headlights still on AUTO, the trailer was magically recognized and trailer brakes continued to work for rest of the trip. Which was damn lucky because I hit an epic rainstorm for the last hour of the journey ....

Some thoughts:

1. in all cases, the trailer brake & running lights work fine, indicating the physical trailer connection is basically fine. While I originally thought this was the culprit, it seems too much coincidence for just the trailer brake pin to be faulty for the people having issues and you would think if this was the case, wiggling the connection etc. might restore the function.
2. however it may be something to do with connection, or grounds, or voltage, or software because out of all the pins, that trailer brake controller is the only "smart" one, so some condition, like headlight status, or moisture or grounds may affect electrical status enough to fool the software
3. but it is not as straightforward as headlight switch to position X fixes the problem, tried that, was fine for a long while and then it happened again!

We need to be able to create the problem and fix it through an action in order to pin down the solution - I didn't have a problem for a month and I could say this was because my headlight switch were in X position, or the stereo was on, or anything else ... but its just opinion unless we can cycle through create/fix/recreate the issue. In my case the problem eventually recurred and wasn't fixed by any of the suggestions on this thread, just (again) randomly and with the passage of time!

Last, if we want Ford's attention on this, anyone who has experienced this problem should be reporting it to NHTSA Report Problem

 

[tderouchie]

So? You wouldn’t. It doesn’t show up automatically. You have to toggle the brake controller manually and read what the gray pop up says. If it says GAIN and nothing else, it’s connected. If it says anything else, it’s not connected. But you have to check. A deliberate action.

I was adding that because I see many people getting that message

 

[tderouchie]

I’m still quite confident that it’s a software issue. When i go see my DTC codes(i work for a ford dealer), every single day I get a code for “lost communication with BCM” and also codes for TRM. Coincidence? We also have many customers with the same code. Thankfully they don’t all tow trailers

 

[JEB]

"Absence of Evidence is not Evidence of Absence"

So, updating my experience ... I had the trailer brake controller fail to recognize the trailer and so fail to function on several occasions in July, including confirming working then failing midway through a journey without any stops/restarts etc. just working, then not working. I've used my trailer (2019 ATC Enclosed Car Hauler) several times and ~ 1,000 miles in August and hadn't had any problems - I've tried multiple suggestions from this thread, headlights switch etc. but could not repeat the issue. Until ... it happened again ?

After spending this past weekend at the track, I made sure the headlights were ON, hooked up my trailer and got nothing ... no trailer attached according to the trailer brake controller. I tried multiple combos, headlight switch OFF, ON and AUTO, letting the car perform a complete shutdown before restarting, unplugging, plugging the physical trailer plug etc. and could not get the trailer brakes to function. So, frustrated, I set off home, headlights on AUTO, stopped after about an hour for gas and a bite to eat and 20 mins later upon returning to truck, started back up, headlights still on AUTO, the trailer was magically recognized and trailer brakes continued to work for rest of the trip. Which was damn lucky because I hit an epic rainstorm for the last hour of the journey ....

Some thoughts:

1. in all cases, the trailer brake & running lights work fine, indicating the physical trailer connection is basically fine. While I originally thought this was the culprit, it seems too much coincidence for just the trailer brake pin to be faulty for the people having issues and you would think if this was the case, wiggling the connection etc. might restore the function.
2. however it may be something to do with connection, or grounds, or voltage, or software because out of all the pins, that trailer brake controller is the only "smart" one, so some condition, like headlight status, or moisture or grounds may affect electrical status enough to fool the software
3. but it is not as straightforward as headlight switch to position X fixes the problem, tried that, was fine for a long while and then it happened again!

We need to be able to create the problem and fix it through an action in order to pin down the solution - I didn't have a problem for a month and I could say this was because my headlight switch were in X position, or the stereo was on, or anything else ... but its just opinion unless we can cycle through create/fix/recreate the issue. In my case the problem eventually recurred and wasn't fixed by any of the suggestions on this thread, just (again) randomly and with the passage of time!

Last, if we want Ford's attention on this, anyone who has experienced this problem should be reporting it to NHTSA Report Problem

Good post. Two things I found highly significant about it. First, this was not an instance where you had a good connection, set off, and then the trailer brake controller randomly lost connection mid-flight. It never connected properly to begin with and you had a great deal of difficulty getting it to do so. That has happened to me as well. Second, when you finally did decide to proceed, you knew beforehand that the trailer brake controller wasn’t communicating properly with the brakes. So, at least you knew what you were dealing with before you set off. And you knew this because you checked!

Have I gotten any of this wrong?

 

[chrisp993]

Have I gotten any of this wrong?

Not wrong so much, but I wanted to stress (i) I didn't have great difficulty, I simply could not get a connection before I set off and (ii) I've long been in habit of checking manually before I set off ... but this isn't much help if the trailer brake function can be lost randomly sometime thereafter. In other words, even if I do have trailer brake function, I'm left with no confidence that it will stay that way - this is no good for short journeys, but would force me sell the truck if I had to take long multi-day journeys w/family or lived in the mountains etc. Last night w/rainstorm I was really lucky to regain function as I couldn't imagine trying to stop the truck/trailer on rain soaked roads with truck brakes only, I would have had to park up and wait out the weather. This situation is so dangerous.

 

[JEB]

I’m still quite confident that it’s a software issue. When i go see my DTC codes(i work for a ford dealer), every single day I get a code for “lost communication with BCM” and also codes for TRM. Coincidence? We also have many customers with the same code. Thankfully they don’t all tow trailers

I agree that it’s software. I’m not sure if the fault codes are related. I just broke out my scanner and it shows no DTC’s even though I had a great deal of trouble connecting the brake controller about 10 days ago.

 

[JEB]

Not wrong so much, but I wanted to stress (i) I didn't have great difficulty, I simply could not get a connection before I set off and (ii) I've long been in habit of checking manually before I set off ... but this isn't much help if the trailer brake function can be lost randomly sometime thereafter. In other words, even if I do have trailer brake function, I'm left with no confidence that it will stay that way - this is no good for short journeys, but would force me sell the truck if I had to take long multi-day journeys w/family or lived in the mountains etc. Last night w/rainstorm I was really lucky to regain function as I couldn't imagine trying to stop the truck/trailer on rain soaked roads with truck brakes only, I would have had to park up and wait out the weather. This situation is so dangerous.

It is dangerous. I agree. But I’m not convinced you’ve ever lost a connection during an ignition cycle. Certainly this last incident isn’t evidence of it. Just the opposite. It worked fine once you confirmed an active connection. And knowing that you don’t have a connection before you move, although far from ideal, is not quite as dangerous because you can always decide not to move. Once underway, you haven’t got a lot of choice.

 

[minirx7]

"Absence of Evidence is not Evidence of Absence"

So, updating my experience ... I had the trailer brake controller fail to recognize the trailer and so fail to function on several occasions in July, including confirming working then failing midway through a journey without any stops/restarts etc. just working, then not working. I've used my trailer (2019 ATC Enclosed Car Hauler) several times and ~ 1,000 miles in August and hadn't had any problems - I've tried multiple suggestions from this thread, headlights switch etc. but could not repeat the issue. Until ... it happened again ?

After spending this past weekend at the track, I made sure the headlights were ON, hooked up my trailer and got nothing ... no trailer attached according to the trailer brake controller. I tried multiple combos, headlight switch OFF, ON and AUTO, letting the car perform a complete shutdown before restarting, unplugging, plugging the physical trailer plug etc. and could not get the trailer brakes to function. So, frustrated, I set off home, headlights on AUTO, stopped after about an hour for gas and a bite to eat and 20 mins later upon returning to truck, started back up, headlights still on AUTO, the trailer was magically recognized and trailer brakes continued to work for rest of the trip. Which was damn lucky because I hit an epic rainstorm for the last hour of the journey ....

Some thoughts:

1. in all cases, the trailer brake & running lights work fine, indicating the physical trailer connection is basically fine. While I originally thought this was the culprit, it seems too much coincidence for just the trailer brake pin to be faulty for the people having issues and you would think if this was the case, wiggling the connection etc. might restore the function.
2. however it may be something to do with connection, or grounds, or voltage, or software because out of all the pins, that trailer brake controller is the only "smart" one, so some condition, like headlight status, or moisture or grounds may affect electrical status enough to fool the software
3. but it is not as straightforward as headlight switch to position X fixes the problem, tried that, was fine for a long while and then it happened again!

We need to be able to create the problem and fix it through an action in order to pin down the solution - I didn't have a problem for a month and I could say this was because my headlight switch were in X position, or the stereo was on, or anything else ... but its just opinion unless we can cycle through create/fix/recreate the issue. In my case the problem eventually recurred and wasn't fixed by any of the suggestions on this thread, just (again) randomly and with the passage of time!

Last, if we want Ford's attention on this, anyone who has experienced this problem should be reporting it to NHTSA Report Problem

I agree, i also tried many different combinations. I also got no warning taht the trailer brakes STOPPED working, when it was working at teh beginning of the drive. VERY dangerous, and the fact that it is happening to many of us makes me believe it is defintely software or some electrical issue.

 

[chrisp993]

I’m not convinced you’ve ever lost a connection during an ignition cycle

JEB, once and for all and as I've stated before this has happened to me on more than one occasion - once, leaving racetrack in July (down a steep hill!) and based on my habit of checking manual operation of the controller I'm pretty certain but OK if under oath I guess not 100% (since the issue hadn't happened to me and so I wasn't taking notice) the trailer brakes were working when I set off and sometime later I noticed they weren't. But - and please actually understand this - having had this issue, when I was trying to diagnose what the heck was happening, I couldn't repeat the issue on my driveway, so I set off to take trailer back storage and you can be *sure* I tested the trailer brakes manually as I set off, found them working and then a mile or so down the road they were not working again. I'm not sure how to "convince you" of this but its pretty irritating to have you simply assume I could be confused on this point.

 

[JEB]

JEB, once and for all and as I've stated before this has happened to me on more than one occasion - once, leaving racetrack in July (down a steep hill!) and based on my habit of checking manual operation of the controller I'm pretty certain but OK if under oath I guess not 100% (since the issue hadn't happened to me and so I wasn't taking notice) the trailer brakes were working when I set off and sometime later I noticed they weren't. But - and please actually understand this - having had this issue, when I was trying to diagnose what the heck was happening, I couldn't repeat the issue on my driveway, so I set off to take trailer back storage and you can be *damn sure* I tested the trailer brakes manually as I set off, found them working and then a mile or so down the road they were not working again. I'm not sure how to "convince you" of this but its pretty irritating to have you simply assume I could be confused on this point.

Ok. Fine. In any event, I have nothing of value left to contribute. And group catharsis isn’t my thing. So, I’m signing off. Good luck, or bon chance, depending on where you hang your hat.

 

[Notallthosewhowanderarelo]

Hi all, I am experiencing the same as most of you.

Sometimes the brakes work, other times not. But lights work all the time and the truck never shows disconnected trailer.

I have a hunch, only a hunch, there may be a grounding issue or supply issue.

The reason I say that is because when I run the slides and electric jack off the truck they are sometimes slow and inconsistent power wise. My old Silverado would easily power my slides and power jack.

So this week I am going to try to get my multimeter out and see if I can find anything. Not sure what I am looking for quite yet, but I have some tests I want to run.

Anyone have tips on testing ground issues with the 7-pin connector?

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