Brake trailer module fault

[JohnnyBoy]

Today I started getting trailer brake module failure. My turn signal blinkers are flashing fast like I have a bulb out. Left or right. Outside my blinkers are working and flashing normal.
I don't have a trailer connected.

Exact same for me last week. Took it in for a different CEL and they fixed it. I'll post their comments later. The receipt is in the truck, the truck is in the parking lot, it's snowing, and I'm in a warm hotel room!

Edit: Went out and got it. All they did was reprogram the module. Hasn't repeated in the 7 days since.

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[Spiffy]

When I last posted I had not picked up the truck. When I got to the service department I met with the adviser and mechanic. The both apologized that the module was on undetermined back order.
My mechanic was super cool. He said he noticed that I had troubles with fdrs and some updates. Everything I do gets recorded. Anyway he said I had a apim update available and he said he didn't want to mess anything I had done up. He wanted to know if I had a tune or custom programming. He stated that he only reset what was necessary to fix the exchanger. He didn't care if i was a hacker. He also loves the hybrid. He asked if I would consider using him in the many visits coming up. He wants me to leave my openpilot in next time. He wants to see it in person.

I drove home and noticed the brake failure was gone. I do remember him poking around my trailer hook up. I have no idea what he did.
Everything on my truck is working perfectly.
I'm still scheduled to return when the module comes in and also get my recalls done.
It's nice that I now have a mechanic that is cool with my messing around and won't throw me under the buss.

 

[Snakebitten]

So sitting at a light with ac running, lights on, lots of current draw. The ice cycles on and off. The starter motor is doing that?

You have 2 12V starters on your truck.

A traditional bendix/flywheel starter
A Belt drive starter.

The 3.5 Ecoboost in the Powerboost only has 2 components connected by belts off the crankshaft pully.
The water pump
The Belt Drive Starter. (blue in the image)
You'll notice it has some serious belt tensioning going on? I assume it's necessary to get a good bite on the crankshaft and spin it up quickly and smoothly.

 

[bloodocean]

Anecdote here:

'23 powerboost, started to get flickering trailer brake failure notifications while driving. one day, after some short trips in cold weather i got a mobile app notification that the truck went into deep sleep to preserve battery voltage.

i decided to just replace the 12V battery and reset the BMS to see what happens. i got one more trailer fault message after that, no flicker, and never again since then. no more deep sleeps either.

 

[Spiffy]

That's really interesting. I love the diagrams thanks! What determines which starter is going to be engaged?
I didn't know there was a belt drive starter.

Is it possible that the belt drive starter is used from a cold start?

I'm interested in learning about normal operations.
1. Cold start. Which starter?
2. Ice starting while stopped. While sitting KOEO. I assume the traction battery's SOC depletes to a certain level and calls for ice to start. Which starter?
3. Driving. Electric drive in combination with ice. Which starter?

You are a fountain of valuable information and I thank you.
I was drawn to the ecoboost for only one reason. The 7k generator. Since then I have been enamored with the the technology. It's like ford decided to build the most complex piece of kit.
It's lucky I'm a techie and have patience with failures. Instead of getting ticked off I get a kick out of learning how it works.
I get ticked off over ford's lack of response and parts.
I almost get bummed that I have to revert to factory repairs. Like how did my mechanic fix the trailer brake module error when they are waiting on the back ordered module. Frustrating!

 

[DRP84]

I had been getting the “Trailer Brake System
Fault” flashing alarm about a month ago. At the dealership the tech concluded they need to replace the module on the bumper that has the 7 pin and 4 pin connectors. I asked about the Trailer Brake Module located inside the cab by the driver’s right leg. He agreed to disconnect it but that just put the fault on steady, so he reconnected it. Once reconnected and restarted I drove home and for the next three weeks had no return of the alert!

Today the fault returned. I have an appointment next Wednesday to replace the 7/4 pin connector module but that just doesn’t feel like it is going to be the solution.

Has anyone had similar experience or advice on how to help the dealership solve this problem?

 

[na8rboy]

It's moisture in connection. Dielectric grease in connection solves the problem.

 

[mrerick]

Which connection? I also am getting the warning intermittently.

 

[Hans Moleman]

I also get it intermittently. I re-seated the fuses and that doesn’t seem to work. Most of the time the trailer brake fault message flashes extremely fast that I can barely see it.

Does this error store a DTC? If not I think the dealer might say they can’t duplicate it.

 

[DRP84]

Wednesday the dealership replaced the 7/4 pin connector. They said mine was packed with sand and salt and that it was intermittently causing the fault when it was wet from rain/snow melt. Drive thru rain and wet roads yesterday without the message returning. They said to try to clean it periodically and regrease it with dielectric grease.

 

[Hans Moleman]

I pulled the DTCs using Forscan and found these 3 codes:

Code: U0140
Lost Communication with Body Control Module
Additional fault symptom (87)
-Missing Message
Module: Trailer Module

Code: U0444
Invalid data received from Body Control Module C
Additional fault symptom (82)
-Alive/Sequence Counter Incorrect/Not Updated
Module: Trailer Module

Code: U0143
Lost Communication with Body Control Module C
Additional fault symptom (87)
-Missing Message
Module: Trailer Module


Does it sound like my trailer brake control module is FUBAR’d ?

 

[ReverendQ]

If misery loves company know that I am so trying to ring this little annoyance out of an otherwise perfect vehicle.

 

[na8rboy]

Which connection? I also am getting the warning intermittently.

The connection on backside of bumper. Plus put som in 7 pin and 4 pin. I did connections at Pro Power as well. A few have been getting faults there as well.

 

[Hans Moleman]

I pulled the DTCs using Forscan and found these 3 codes:

Code: U0140
Lost Communication with Body Control Module
Additional fault symptom (87)
-Missing Message
Module: Trailer Module

Code: U0444
Invalid data received from Body Control Module C
Additional fault symptom (82)
-Alive/Sequence Counter Incorrect/Not Updated
Module: Trailer Module

Code: U0143
Lost Communication with Body Control Module C
Additional fault symptom (87)
-Missing Message
Module: Trailer Module


Does it sound like my trailer brake control module is FUBAR’d ?

My dealer performed TSB 24-2116 which applies to only PB trucks with the trailer brake fault error message. It is a software update for the APM, GWM, & TRM modules. I’ll give it a few and see if this TSB actually works.

 

[Spiffy]

I also get it intermittently. I re-seated the fuses and that doesn’t seem to work. Most of the time the trailer brake fault message flashes extremely fast that I can barely see it.

Does this error store a DTC? If not I think the dealer might say they can’t duplicate it.

That's bullshit when the dealership says they can't replicate

I also get it intermittently. I re-seated the fuses and that doesn’t seem to work. Most of the time the trailer brake fault message flashes extremely fast that I can barely see it.

Does this error store a DTC? If not I think the dealer might say they can’t duplicate it.

I went through all of this. First trip they messed with the cable. That worked fir a week. Then they decided to replace the controller. I put a scope on the bus. Traced it back to the module. The data to the controllers reciver was intermittent.
The Part that I called bullshit was when they said it needed to fail in front of them. I showed them the recorded data.
Besides the DLC is still in past data. Sometimes the module shows up and other times the module not on the bus.
That controller is the fault. If I unplug the controller when it throwing faults the faults go away. I told the mechanic if they won't replace the module i will short the data high to data low. That way the fault will be there always.
The mechanic finally Said fine I will replace the module. Four week wait it got replaced. Problem solved.
I don't understand why they have to witness the fault when it's clearly in past data.

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