Trailer brake not working

[rpeterslll]

File a report with the NHTSA if you haven’t already. They contacted me and I now have Ford Requesting an inspection of my truck regarding it.

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[minirx7]

Took out the RV today for the first time since August 29th .. Went for an over night trip to winterizing, wash/wax etc .

Low and behold, trailer brakes work perfectly all day, and al thorugh the drive. No issues at all.

The only explanation for this is the temperature.. It is much cooler outside,.

 

[CoastalOptions]

I have this problem too, '21 PowerBoost purchased Mon 9/27 right off the delivery truck (Rep called me to come in ASAP).

Purchased 6-Month old K-Z 31' Connect on Wed 9/29. Got the whole thing leveled with the sway bars and such, all lights, and everything works fine (used the Ford App). No brakes.

Temp was 85 degrees between 2-5 pm here in FL while trying to set up.

Re-Hitch it to his RAM 2500, brakes are fine. Re-Hitch back to 2 day old Powerboost - no brakes.

$72k truck and seriously, WTF?

(I'll try the grease, spray, plug in while the truck is off recommendations)

 

[minirx7]

I have this problem too, '21 PowerBoost purchased Mon 9/27 right off the delivery truck (Rep called me to come in ASAP).

Purchased 6-Month old K-Z 31' Connect from Wed 9/29. No brakes. Got the whole thing leveled with the sway bars and such, all lights, and everything works fine (used the Ford App). No freaking breaks.

Temp was 85 degrees between 2-5 pm here in FL while trying to set up.

Re-Hitch it to his RAM 2500, brakes are fine. Re-Hitch back to 2 day old Powerboost - no brakes.

$72k truck and seriously, WTF?

(I'll try the grease, spray, plug in while truck is off recommendations)

Try this and let us know if this works>
1. Car off
2. Get compressed air or anything that can cool teh connectors down in temperature
3. Plug in
4. Start the car
5. Turn on the headlights
6. Pull the trailer brake


See if that works. The only reason i blieve i had no issues in my RV trip this week was because the tmperature was very cold outside (and i always turned on my headlights which i realy dont think has any impact)./

 

[Ford Motor Company]

I have a new 2021 f150 power boost.

I purchased a 2020 airstream and towed it 10.5 hours from Wisconsin to Nebraska.

I set the trailer brake fine in Wisconsin and it seemed to be working without issue. I did mess with the gain a lot trying to get it right.

I parked in my driveway for 3 days and when i towed it to storage, the trailer brake was not working.

It would show my trailer connected, and allow me to select the trailer, but when I would try to manually squeeze the trailer brake a screen popped up saying “no trailer” and the brakes were clearly not engaging. (I noticed this because I could tell I was getting pushed when i got off an exit ramp.)

Anyone seen this happen? I checked the 7 pin connector and it looks like new. I was thinking it may be a fuse in the truck - but didn’t have time to check.

When the trailer is not connected at all the message from the trailer brake is a bit different, showing a pop up that shows trailer disconnected. When trailer was connected, it popped up like it should - but underneath the gain settings shows “no trailer” and the brakes don’t work.

I should also add that the signal lights, brake lights and everything else seem to be working on the airstream.

Good morning! Would you please send over a private message with your VIN? I would like to look into your trailer brake issue on my end.

 

[UGADawg96]

Good morning! Would you please send over a private message with your VIN? I would like to look into your trailer brake issue on my end.

How about getting engineering to look at this thread. Thank you.

 

[Canuqq]

I just came back from a 5 day trip to a Provincial Park a few hours away. I wanted to keep detailed records on how and when the trailer brakes did and didn't work for me so I could provide more details to the service manager at my dealer. I thought I would try Tambow's idea of moving the keys away from the truck to see if that helped. Here are the details of what happened:

I hooked the truck up to the RV trailer last Thursday, immediately pressed the gain button and the brakes appeared to be working (the “no trailer” message did not appear on the dashboard display). But when I got to the end of our driveway (300 metres) and squeezed the brake controller the trailer brakes were not applied. I shut the truck off and waited a few seconds to turn if back on. I then pressed the gain button and the “no trailer” message appeared. I shut the truck off again and walked a couple of hundred metres away from the truck with the keys.

I walked back to the truck, started it, squeezed the brake controller and the trailer brakes were applied so we headed off. Partway to the Park, I felt that the trailer brakes were not engaging when I pressed the brake pedal. I slowed down & squeezed the brake controller and the trailer brakes were not applied. The trailer brakes didn’t work for the rest of the trip to the Park.

When we headed home from the Park, I connected the trailer to the truck, moved forward a few feet, squeezed the brake controller and the trailer brakes were applied. We drove a few hundred metres to say goodbye to friends and I turned the truck off. When we returned to the truck and turned it on, I squeezed the brake controller and to my dismay the trailer brakes were not applied. We drove a few hundred metres to the dump station and turned off the truck to empty our black & grey tanks. While the tanks were emptying my wife walked away from the truck with both keys as a test. When she returned to the truck & I turned the truck on, the trailer brakes were applied when I squeezed the brake controller. We left the truck running during any errands that we had to do on the way home. I tested the trailer brakes by squeezing the brake controller several times on the way home and the brakes continued to work. It’s so frustrating never knowing whether the trailer brakes are going to work or not!!! And why does walking away from the truck with the keys seem to make the brake controller work again? Is this just a coincidence?

Based on my experience, I don't think the problem is temperature related, as the brakes both worked and didn't work within a short period of time in exactly the same temperature conditions

I've taken the truck in to my local dealer and they are having a look at it.

 

[Tambow]

I’ve been on the road for four weeks now towing the 21 Airstream and now have lots of practice with the issue. I’m still not sure what is causing the failure, but I have found a reliable fix. When ever the brakes randomly fail I pull over and turn off the truck and lock it. I go away from the truck so my key isn’t recognized for about 5 or 10 minutes. When I return the brakes work again. I’ve tried shorter times but if I return to quickly the brakes still don’t work. They failed twice yesterday in the mountains of Maine but I was able to get them working again. I think the truck just needs to reboot like a computer or your cell phone. It’s basically a big computer. Hope this helps.

 

[rpeterslll]

I’ve been on the road for four weeks now towing the 21 Airstream and now have lots of practice with the issue. I’m still not sure what is causing the failure, but I have found a reliable fix. When ever the brakes randomly fail I pull over and turn off the truck and lock it. I go away from the truck so my key isn’t recognized for about 5 or 10 minutes. When I return the brakes work again. I’ve tried shorter times but if I return to quickly the brakes still don’t work. They failed twice yesterday in the mountains of Maine but I was able to get them working again. I think the truck just needs to reboot like a computer or your cell phone. It’s basically a big computer. Hope this helps.

Have you tried keeping the truck off for the 5 or 10 minutes to see if it reset with the key near? What’s the outside temp like when this occurred?

 

[JnDArchie]

I have a case number with Ford customer service for this issue and I’m taking it to the dealer this week for them to inspect the vehicle. I will share this information with them. Hopefully it will be a help.

 

[rpeterslll]

I have a case number with Ford customer service for this issue and I’m taking it to the dealer this week for them to inspect the vehicle. I will share this information with them. Hopefully it will be a help.

Ford will also be inspecting my vehicle this week for the issue.

 

[turbopilot]

A few hints about what is going on with these brake controllers. I plugged in a 7 pin analyzer to the trailer plug on my 2021 F-150 PowerBoost. About every 10 seconds the LED flashes on Pin 2 (Blue wire) that goes to the brakes. So it appears the brake controller is strobing the brake magnets looking for some electrical signature to confirm the brakes are attached.

Then I came across this very interesting technical paper titled "Electric Brake Assembly Temperature Differences Measured by Electromagnet Currents". It appears the current passed through the brake magnets is inversely proportional to the temperature. In other words hot electric trailer brakes pass less current.

I have read so many posts relating temperature to brake controller "failure" and then all the stories about shutting down the truck for 10 or 15 minutes restoring the brake controller. Could it be that the magnets are cooling allowing the "right" electrical signature to be sensed by the brake controller during these shut downs?

Obviously the immediate solution would be to fool the brake controller into thinking the brakes are always present. But I have no idea how you would do this.

 

[chrisp993]

I have read so many posts relating temperature to brake controller "failure" and then all the stories about shutting down the truck for 10 or 15 minutes restoring the brake controller. Could it be that the magnets are cooling allowing the "right" electrical signature to be sensed by the brake controller during these shut downs?

FWIW, I've had the trailer brakes fail partway through a journey (= hot?) and also fail i.e. not present from cold start, truck had been sitting for hours (= cold?) and then re-appear midway through several hundred mile journey home after being shut down (rest stop) for 15mins.

I don't think its related to the brakes getting hot. But I don't have any theories either ...

 

[Ford Motor Company]

I just came back from a 5 day trip to a Provincial Park a few hours away. I wanted to keep detailed records on how and when the trailer brakes did and didn't work for me so I could provide more details to the service manager at my dealer. I thought I would try Tambow's idea of moving the keys away from the truck to see if that helped. Here are the details of what happened:

I hooked the truck up to the RV trailer last Thursday, immediately pressed the gain button and the brakes appeared to be working (the “no trailer” message did not appear on the dashboard display). But when I got to the end of our driveway (300 metres) and squeezed the brake controller the trailer brakes were not applied. I shut the truck off and waited a few seconds to turn if back on. I then pressed the gain button and the “no trailer” message appeared. I shut the truck off again and walked a couple of hundred metres away from the truck with the keys.

I walked back to the truck, started it, squeezed the brake controller and the trailer brakes were applied so we headed off. Partway to the Park, I felt that the trailer brakes were not engaging when I pressed the brake pedal. I slowed down & squeezed the brake controller and the trailer brakes were not applied. The trailer brakes didn’t work for the rest of the trip to the Park.

When we headed home from the Park, I connected the trailer to the truck, moved forward a few feet, squeezed the brake controller and the trailer brakes were applied. We drove a few hundred metres to say goodbye to friends and I turned the truck off. When we returned to the truck and turned it on, I squeezed the brake controller and to my dismay the trailer brakes were not applied. We drove a few hundred metres to the dump station and turned off the truck to empty our black & grey tanks. While the tanks were emptying my wife walked away from the truck with both keys as a test. When she returned to the truck & I turned the truck on, the trailer brakes were applied when I squeezed the brake controller. We left the truck running during any errands that we had to do on the way home. I tested the trailer brakes by squeezing the brake controller several times on the way home and the brakes continued to work. It’s so frustrating never knowing whether the trailer brakes are going to work or not!!! And why does walking away from the truck with the keys seem to make the brake controller work again? Is this just a coincidence?

Based on my experience, I don't think the problem is temperature related, as the brakes both worked and didn't work within a short period of time in exactly the same temperature conditions

I've taken the truck in to my local dealer and they are having a look at it.

Hi there, Jim! Can you send us a DM with your VIN and mileage so I can look into the issue with your brakes on my end?

 

[Tambow]

Have you tried keeping the truck off for the 5 or 10 minutes to see if it reset with the key near? What’s the outside temp like when this occurred?

Update.

We did try another approach yesterday when we lost brakes in Maine. We pulled over, turned off the car and just sat in the car until all of the screens went dark. It took 10 minutes for the truck to turn off fully. And it worked. When we started the truck up again the brakes were back. So I now have a modified approach. I still think the truck needs to fully reboot but now I think waking away with the key is not necessary. Just sit in the truck until it turns off fully. The temp was about 60 degrees. The other day when they failed twice it was in the 50’s and kind of raining a bit. i still can’t put my finger on anything specific that could cause the failure though.

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