Trailer brake not working

[JEB]

Yes indeed. If it happens on my next outing I will probably proceed to file a complaint with the NTSB. This could have devastating consequences!

NHTSA is where you want to file a complaint of this kind.

Sponsored

 

[JEB]

Today, we started shopping for a new truck.

Yesterday, the orange "Trailer Disconnected" popped up while descending a 6% grade with an 8500lb load. Interestingly, squeezing the manual brake did show it working on screen — but it was all a lie. We used the transmission to help slow the vehicle for the remainder of the descent. When it was over, our brakes were smoking.

This is the third time we've experienced such an event.

Ford, if you pay attention to this thread you should say something before the lawyers do.

I have learned to ignore the orange “trailer disconnected” and “trailer connected” pop ups when it comes to the brake controller. They don’t appear to be related to the trailer brake connection, which is itself dangerous. But if you were interrogating the trailer brake controller directly by activating the manual override or changing the gain and the brake controller pop up was showing a connection, then I suspect your brakes were working notwithstanding the other pop up which relates more to the profiles than brake control.

Threatening a company famous for the Pinto with lawyers is not likely to get you far.

 

[JEB]

OK, picked up my trailer - started with headlights OFF, plugged in trailer and, trailer brake tested OK, drove away and tried switching headlights from OFF to ON to AUTO, made no difference, trailer brakes worked fine under all cases. I'm not saying there isn't something going on with the software / electrical configuration, but it isn't as simple as headlights ON = brakes working. Additionally, when I've had the trailer brakes stop working during a journey, its been with headlights on AUTO but during the afternoon on open road, so nothing related to headlights would have switched ON or OFF to cause the malfunction. I'm still stumped ...



Yup, I'm really surprised this issue exists, let alone seems relatively widespread ...

I haven’t tested cycling the lights after a successful connection like you have. All I know is that if my lights are on when I connect and I’m not moving, everything works fine for at least that ignition cycle. It’s hard to know what to make of your experiment, which was basically to induce a failure once you connected successfully. Maybe the system isn’t quite that stupid and is programmed to retain a connection once established until the next ignition cycle. But your Auto observation kind of proves my point. If you stopped during your journey on a bright sunny day and restarted after the headlights defaulted to AUTO, you were restarting with the headlights OFF because the AUTO function determined you did not need headlights on a bright sunny day, which means no 12v and no brake connection. This makes perfect sense to me.

Having the lights on whenever towing is common for people who tow travel trailers. 12v auxiliary power is necessary keep the house batteries charged and systems like wireless cameras attached to the rear of the trailer powered. And Ford is not the only truck manufacturer that requires the headlights to be on to keep the 12v system active—Chevy does this as well. So, people towing travel trailers that have learned reflexively to tow with their lights on might not necessarily know about the trailer brake issue if by habit they routinely switch out of auto and turn the lights on. Where Ford seems to have made a dangerous mistake is tying the brake controller recognition to activity on the 12v circuit. For those towing trailers that do not require active use of that circuit, the brake controller might not recognize that a trailer is connected and the drivers wouldn’t know it until after they are already underway and need them.

At this point, I’m not going to worry about it further. I haven’t experienced a mid-ignition cycle disconnect and your experiment might actually show that it isn’t likely. You weren’t able to induce a failure. You got a disconnect only after you actually shut down and restarted with the system defaulting to AUTO. So, I will just continue to make sure the headlights are on when I connect and before I start moving and the brake controller separately shows a positive connection. If it disconnects during an ignition cycle, then I’ll worry.

 

[chrisp993]

Jeb, just to clarify again, I experienced a disconnect while driving along without stopping or restarting etc. At one time in at least two trips I've made the trailer brakes were working, then later in the same continuous journey they weren't without any change in headlight switch or headlights needing to be On. I appreciate the efforts to sleuth but unless we're able to turn a failure on or off they are just ideas.

Like you, I'll worry less if it doesn't happen again, but it'll still be at the back of my mind and luckily I'm in flatland Midwest. I feel for anyone with a large trailer and hills.

 

[JEB]

Jeb, just to clarify again, I experienced a disconnect while driving along without stopping or restarting etc. At one time in at least two trips I've made the trailer brakes were working, then later in the same continuous journey they weren't without any change in headlight switch or headlights needing to be On. I appreciate the efforts to sleuth but unless we're able to turn a failure on or off they are just ideas.

Like you, I'll worry less if it doesn't happen again, but it'll still be at the back of my mind and luckily I'm in flatland Midwest. I feel for anyone with a large trailer and hills.

Then I recommend you keep a journal. Ignore ALL prior experiences and start from scratch. Make sure you only connect the trailer with the headlights in the ON position—ON only, not some other position—and that you verify the connection via manual operation of the brake controller before you start moving. Write it down. Then log every incident where you experience a mid-ignition cycle disconnect, if any. This way, you will verify whether the procedure works or not.

 

[Kanuck]

I found that when doing a trailer light check on Ford Pass, that the running lights on the trailer were not working. But when I turned the lights on, they did work. I took the truck in to the dealer. They had to order a module. When they replaced it and tested the system, it threw a code. After about a week, I was informed that the dealer was told by ford engineering not to worry about this PHAMTON code. Just wondering if all these issues are because of the trailer control module failing.

 

[JEB]

I found that when doing a trailer light check on Ford Pass, that the running lights on the trailer were not working. But when I turned the lights on, they did work. I took the truck in to the dealer. They had to order a module. When they replaced it and tested the system, it threw a code. After about a week, I was informed that the dealer was told by ford engineering not to worry about this PHAMTON code. Just wondering if all these issues are because of the trailer control module failing.

That is not unusual. The running lights on your trailer are generally synced to the taillights on your truck. The truck taillights are on only when the headlights are on. So, your trailer running lights likewise should be on only when your headlights are on. This is normal operation.

 

[Kanuck]

That is not unusual. The running lights on your trailer are generally synced to the taillights on your truck. The truck taillights are on only when the headlights are on. So, your trailer running lights likewise should be on only when your headlights are on. This is normal operation.

I agree, but when you do the trailer light check, the running lights are turned on at the start and stay on during the whole test. In my case, the truck lights were on but not on the trailer.

 

[JEB]

I agree, but when you do the trailer light check, the running lights are turned on at the start and stay on during the whole test. In my case, the truck lights were on but not on the trailer.

Interesting. That has not been my experience. The trailer light check hasn’t worked for me from the FordPass app unless the truck, including the headlights, were on.

I think tederouchie’s experience is spot on. This issue has nothing to do with the brake controller module. He had his replaced and it didn’t fix the problem.

The issue is programming.

 

[tderouchie]

I found that when doing a trailer light check on Ford Pass, that the running lights on the trailer were not working. But when I turned the lights on, they did work. I took the truck in to the dealer. They had to order a module. When they replaced it and tested the system, it threw a code. After about a week, I was informed that the dealer was told by ford engineering not to worry about this PHAMTON code. Just wondering if all these issues are because of the trailer control module failing.

I think We all have this code

 

[tderouchie]

I’ve noticed a pattern on mine that the trailer brakes quit after being stopped for 1+mins and holding the brakes. The failure has occurred at least five times right after being stopped for a short period of time (red light, ferry, etc) since mid-June. Maybe someone else will notice this pattern and help Ford come up with a solution.
I will definitely be trying to run with my headlights on as well.

 

[justinwvu]

I’ve noticed a pattern on mine that the trailer brakes quit after being stopped for 1+mins and holding the brakes. The failure has occurred at least five times right after being stopped for a short period of time (red light, ferry, etc) since mid-June. Maybe someone else will notice this pattern and help Ford come up with a solution.
I will definitely be trying to run with my headlights on as well.

I like the diary idea. Maybe we all have the same problem or maybe we have different issues causing a very similar presentation. Seems like it is so similar though that it has to be some sort of problem with the trucks electronic control system. Why else would so many of us be having this?

I plan to clean my connections really good, and then apply conductive grease prior to my next trip.

If the problem was just getting it to start working before departure that would be one thing, but when it stops working while driving without any warning that is the biggest issue.

 

[wmwalker]

I’ve noticed a pattern on mine that the trailer brakes quit after being stopped for 1+mins and holding the brakes. The failure has occurred at least five times right after being stopped for a short period of time (red light, ferry, etc) since mid-June. Maybe someone else will notice this pattern and help Ford come up with a solution.
I will definitely be trying to run with my headlights on as well.

That’s interesting. On one occasion we did lose brakes after being stopped at a train. Unfortunately I don’t recall if I just held the brakes the entire time or had it in park.

 

[JEB]

That’s interesting. On one occasion we did lose brakes after being stopped at a train. Unfortunately I don’t recall if I just held the brakes the entire time or had it in park.

This, from p. 372 of the 2021 owner’s manual. “Note: If your vehicle does not recognize the trailer, press and hold the brake pedal for a few seconds.”

I wonder if you had the headlights off at the time you held the brake pedal down, triggering a new recognition cycle, and the software thought you no longer had a trailer attached.

 

[tderouchie]

I plan to clean my connections really good, and then apply conductive grease prior to my next trip.

That’s not a bad thing to do, but unfortunately won’t fix the issue. I have a brand new 7pin harness(rv side and truck side), new ground, etc and all well greased with Ford electrical grease(not dielectric) and no better.

Sponsored