Towing issue - Trailer Brake Controller seemingly spiking trailer brakes full on/off under hard braking or using manual slider

[rxsamg]

Having an odd issue with my '22 F150 PB hooked up to an 18" open car hauler that has twin axle electric brakes. Never had this issue with my '12 F150.

After having the trailer sit all winter, I picked it up out of storage for the 1st time using the new truck and pretty sure I setup the trailer options correctly but noticed an odd behavior of the trailer brakes. Everything seems fine during normal braking BUT if I try hard braking or use the controller slider to full braking, the controller seems to switch between full trailer brake power & zero brake power causing a hard jerkiness between the truck & trailer. Best way to describe it is it's like a slow motion ABS on the trailer (like 0.25 or 0.5 second full on, followed by same time amount off)

I have tested: low gain, medium gain, high gain, trailer loaded, trailer unloaded. The exact same symptom happens. It's easily identified by watching the trailer gain monitor in tow status jumping from full gain to zero and repeats ONLY under hard braking or using full slider control WHILE truck is moving. If stopped max brake pressure or slider maintains max gain on meter & doesn't blip down.

I'm going to hook up the trailer to a friend's truck to rule out any issues with the trailer's own brakes/wiring but it's only ~3 yrs old & was working perfectly on my old truck 5 months ago before it sat idle thru the winter. Other option is to swing by my local trailer dealer & test pull a new comparable trailer.

Anyone ever experience similar? Researching I can't find anything showing similar behavior, everything just points to either the controller unit itself or the wiring. I did find a new trailer brake controller recall that supposedly address an issue with the controller software and supposedly it's a fix of a previous recall.

Been trying to search if it's the same behavior but all both recalls indicate are "loss of trailer brake functionality" I'm having a ford tech buddy of mine check OASIS tomorrow, but my truck's build date is 2/2022 might be right at the cutoff of the original recall (if that's even the cause) and Ford's online check of my VIN 1FTFW1ED0NFA63565 doesn't appear to show impacted

Original recall, but can't find if my VIN was impacted
https://www.f150gen14.com/forum/thr...elay-module-campaign-nhtsa-22s17-22v193.9742/

New recall just announced but supposedly only affects 10k vehicles
NHTSA Campaign Number 25V132000 is a recall by Ford Motor Company affecting 10,627 vehicles. The recall addresses a potential issue with the integrated trailer brake control module where the trailer brakes might not engage, potentially leading to longer stopping distances and increased crash risk. This recall specifically targets vehicles that were previously repaired under recall 22V-193 but where the software fix was not fully applied.

Sponsored

 

[Buyer2021]

I'm going to hook up the trailer to a friend's truck to rule out any issues with the trailer's own brakes/wiring

Sounds like a good next step ..... look forward to hearing results of that test.

 

[powerboatr]

Sounds like you checked everything
But..for good measure
Trailer emergency battery for charge
And ground to frame of trailer solidly connected at both ends
Love the mustang

 

[rxsamg]

Sounds like you checked everything
But..for good measure
Trailer emergency battery for charge
And ground to frame of trailer solidly connected at both ends
Love the mustang

Thx
Battery checked. All good. Breakaway cable has no tension too.
Ground hmmmm, will check it. Didn’t consider that.

 

[JEB]

Having an odd issue with my '22 F150 PB hooked up to an 18" open car hauler that has twin axle electric brakes. Never had this issue with my '12 F150.

After having the trailer sit all winter, I picked it up out of storage for the 1st time using the new truck and pretty sure I setup the trailer options correctly but noticed an odd behavior of the trailer brakes. Everything seems fine during normal braking BUT if I try hard braking or use the controller slider to full braking, the controller seems to switch between full trailer brake power & zero brake power causing a hard jerkiness between the truck & trailer. Best way to describe it is it's like a slow motion ABS on the trailer (like 0.25 or 0.5 second full on, followed by same time amount off)

I have tested: low gain, medium gain, high gain, trailer loaded, trailer unloaded. The exact same symptom happens. It's easily identified by watching the trailer gain monitor in tow status jumping from full gain to zero and repeats ONLY under hard braking or using full slider control WHILE truck is moving. If stopped max brake pressure or slider maintains max gain on meter & doesn't blip down.

I'm going to hook up the trailer to a friend's truck to rule out any issues with the trailer's own brakes/wiring but it's only ~3 yrs old & was working perfectly on my old truck 5 months ago before it sat idle thru the winter. Other option is to swing by my local trailer dealer & test pull a new comparable trailer.

Anyone ever experience similar? Researching I can't find anything showing similar behavior, everything just points to either the controller unit itself or the wiring. I did find a new trailer brake controller recall that supposedly address an issue with the controller software and supposedly it's a fix of a previous recall.

Been trying to search if it's the same behavior but all both recalls indicate are "loss of trailer brake functionality" I'm having a ford tech buddy of mine check OASIS tomorrow, but my truck's build date is 2/2022 might be right at the cutoff of the original recall (if that's even the cause) and Ford's online check of my VIN 1FTFW1ED0NFA63565 doesn't appear to show impacted

Original recall, but can't find if my VIN was impacted
https://www.f150gen14.com/forum/thr...elay-module-campaign-nhtsa-22s17-22v193.9742/

New recall just announced but supposedly only affects 10k vehicles
NHTSA Campaign Number 25V132000 is a recall by Ford Motor Company affecting 10,627 vehicles. The recall addresses a potential issue with the integrated trailer brake control module where the trailer brakes might not engage, potentially leading to longer stopping distances and increased crash risk. This recall specifically targets vehicles that were previously repaired under recall 22V-193 but where the software fix was not fully applied.

The recall (and the re-recall) doesn’t address the condition you are experiencing. The recall problem was a software glitch that caused the trailer brakes not to engage at all because the trailer brake controller failed to detect that a trailer was attached. The re-recall was because some dealers reprogrammed the TRM thinking they were applying the software that corrected the problem but were actually just applying an older and still buggy version that was still on the FDRS server. That re-recall only affects trucks that were reprogrammed with non-corrective software between approximately February 2022 and May 2022.

Not hard to determine if the software in your TRM is up to date. Just look at the as-built data and see if your strategy version ends in -BB or higher. If it does, the recall and the re-recall don’t affect you.

 

[powerboatr]

Thx
Battery checked. All good. Breakaway cable has no tension too.
Ground hmmmm, will check it. Didn’t consider that.

Ever since day one in 05
The integrated controller and system
Has had a thing for grounds
Habit..now it's a first check,
Keep us posted

 

[FirstFord]

Ever since day one in 05
The integrated controller and system
Has had a thing for grounds
Habit..now it's a first check,

I'm curious - can you expand? In your experience, has the integrated controller system had issues not being being properly grounded, or is it that the controller is hypersensitive to a trailer that has ground issues?

 

[powerboatr]

I'm curious - can you expand? In your experience, has the integrated controller system had issues not being being properly grounded, or is it that the controller is hypersensitive to a trailer that has ground issues?

The system as a whole.
The ground signal gets lost and causes a high percentage of errors in lights and brakes
The controller works well
Imo
No body thought much about the trailer wiring, very much prior to the tbc as factory option.
It was not uncommon for people to assume the ball would be ground enough
The emergency brake battery is another one of those..gotcha items
Truck sends charge to it, but battery cells are bad so it causes faults
In last few years with led lights etc
The system has become even more
Sensitive to electrical gremlins.
Which in turn makes good grounds, and connections even more important

 

[rxsamg]

The recall (and the re-recall) doesn’t address the condition you are experiencing. The recall problem was a software glitch that caused the trailer brakes not to engage at all because the trailer brake controller failed to detect that a trailer was attached. The re-recall was because some dealers reprogrammed the TRM thinking they were applying the software that corrected the problem but were actually just applying an older and still buggy version that was still on the FDRS server. That re-recall only affects trucks that were reprogrammed with non-corrective software between approximately February 2022 and May 2022.

Not hard to determine if the software in your TRM is up to date. Just look at the as-built data and see if your strategy version ends in -BB or higher. If it does, the recall and the re-recall don’t affect you.

TRM - Trailer Module
Part number: MU5T-19J294-DJ
Calibration level: MU5T-19J294-DJ
Strategy : ML3T-19J297-BB

So the recall & re-recall do not affect my truck, was hoping it would have been that & a quick software fix. I'll be testing ground & other things when I grab my trailer Saturday & have time to mess with it.

 

[JEB]

TRM - Trailer Module
Part number: MU5T-19J294-DJ
Calibration level: MU5T-19J294-DJ
Strategy : ML3T-19J297-BB

So the recall & re-recall do not affect my truck, was hoping it would have been that & a quick software fix. I'll be testing ground & other things when I grab my trailer Saturday & have time to mess with it.

No, the recalls do not affect your truck. You have the fix. But that isn’t the same as fully up to date. The most recent version ends in -CC. But I think a software update is an unlikely fix for your issue.

 

[Kanuck]

The system as a whole.
The ground signal gets lost and causes a high percentage of errors in lights and brakes
The controller works well
Imo
No body thought much about the trailer wiring, very much prior to the tbc as factory option.
It was not uncommon for people to assume the ball would be ground enough
The emergency brake battery is another one of those..gotcha items
Truck sends charge to it, but battery cells are bad so it causes faults
In last few years with led lights etc
The system has become even more
Sensitive to electrical gremlins.
Which in turn makes good grounds, and connections even more important

I have rewired a few trailers in my time and 65% of problems is the ground being corroded. The other 35% is cheap 4 conductor wire being used and not protected or attached. I use the wire that is used on semi trailers. A little more costly, but I only do the job once.

 

[Kanuck]

My mind is wandering again.... Some day I will get to stay around..

Does anyone know if the trailer brakes have Anti Lock braking programed in to the logic.

 

[Buyer2021]

Does anyone know if the trailer brakes have Anti Lock braking programed in to the logic.

True anti-lock requires wheel speed sensors with feedback to the controlling system, so, no.

The TBC has no way of knowing whether a trailer wheel is rotating or not. I can easily lock my trailer brakes on loose gravel with the manual lever, or with the brake pedal if the gain is not adjusted for that surface.

 

[rxsamg]

Update: Tested trailer on buddy’s truck. Functioned perfectly correct. Issue is somewhere between the TBC itself and the 7 pin outlet.

Ironically I have a new 7 pin outlet AND rear cable wiring that I have yet to install (soon) so I can connect trailer camera/TPMS/Yaw kit that I have. I might wait to investigate further with TBC until cables/plug swapped and essentially ruled out.

Is there a service procedure/test I can run on the TBC via forscan? Want to make sure before I try since I need to reflash ECU back to stock tune in order to connect via forscan.
(And before anyone asks, behavior was same on stock tune prior, so that’s not a factor)

 

[Buyer2021]

Update: Tested trailer on buddy’s truck. Functioned perfectly correct. Issue is somewhere between the TBC itself and the 7 pin outlet.

Thanks for that informative update / test result

Is there a service procedure/test I can run on the TBC via forscan?

Maybe no help but FYI / FWIW attached are the System Operation and Diagnosis and Testing sections from the Workshop Manual (trailer brakes are referenced as "Auxiliary Brake System" in the WSM).

Good luck.

Sponsored