Brake trailer module fault

[Spiffy]

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. I have picked up on a few old discussions but Noone bothers to text back if they got it resolved. I hate that! If you find a solution then post it please. Mini rant

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[Spiffy]

Bump. Have appointment to get my midpipe heat exchanger replaced Thursday.

 

[JLJ742]

Was looking into a similar issue and had tagged this post where the cause was a blown fuse causing the same issues.

https://www.f150gen14.com/forum/thr...e-fault-message-wont-go-away.4205/post-323658

 

[Spiffy]

Thank you for the link. There was a common detonator in everyone's success to rectify the issue. They all pulled and reset the fuse. Their thoughts were loose fuses. I'm thinking that pulling the fuse cut power to the module thus rebooting the unit.
I have a 2022 hybrid and even if I have stopped the truck and removed the keys I see that several modules are consistently powered. The 12 volt battery always has a parasitic draw of around 1 amp. The 12v battery is supplied proper voltage during this power off draw by the hybrid battery.

If the 12v battery is consistently being depleted the truck goes into deep sleep mode. Every device that is currently being supplied power after shutdown is turned off..

Systems that draw power always regardless of engine on or off consists of security, communications modem, battery monitoring, and several others. My truck consistently has clicking and clacking from different relays even after 12 hours.
I notice my sync system starts up in seconds when I push the start button. The only way it can go through the boot up that fast is because it sees approaching movement with the 360 cameras. I always hear relays clicking when I approach my truck. It's like it's ready to give full accessories the very moment I push the button to start. Android auto has already connected to my phone and my music from my streaming service starts to play before I even release my finger . So something is always running taking power from battery.

It's possible that even disconnecting the 12v battery won't reset the trailer module because I still have the traction battery supplying power. I don't ever recall hearing the starter motor run. It's alway starts the engine by the electric drive motor.

I guess if this keeps coming back even if I pull the fuse then I have a bad module.

I did read yesterday that some say I need to do a software update to the trailer module.

The only thing I need to know is what fuse to pull. I read some have pulled different fuses because of different vehicles.

 

[JEB]

It's possible that even disconnecting the 12v battery won't reset the trailer module because I still have the traction battery supplying power. I don't ever recall hearing the starter motor run. It's alway starts the engine by the electric drive motor.

That's not quite the way it works. The traction/hybrid battery does nothing to start the motor. There are two 12v batteries on the Powerboost--the traditional starter battery under the hood and a smaller 7.5Ah auxiliary battery under the rear passenger-side seat. The auxiliary battery supplies temporary power to modules when the starter battery is disconnected or tied up doing other things, like starting the motor. That's why disconnecting the starter battery doesn't depower your modules. The auxiliary is keeping them live. The hybrid battery is not involved.

 

[Spiffy]

Good to know. But still based on other comments people had luck fixing there trailer module by removing the fuse that goes to it. Many people said that. It's quite possible that removing the power to the module would in effect cause a reboot. What do you think?

 

[Spiffy]

BTW I was sure I read that the hybrid traction battery helped keep up the main 12volt battery. We know there is no alternator so something has to be responsible for charging the 12v upfront and under rear seat batteries.

When I push the start button my truck usually just turns on. Engine not running. Then when called for the traction motor starts the engine. I think I have only heard the mechanical starter engage to start the engine.
So what's going on?

 

[JEB]

Good to know. But still based on other comments people had luck fixing there trailer module by removing the fuse that goes to it. Many people said that. It's quite possible that removing the power to the module would in effect cause a reboot. What do you think?

On a Powerboost, cutting the power to the module to reset it by pulling the fuse is fine as long as you give it enough time to fully power down. Some modules have capacitors which store energy, however, so it can take a while for them to fully reset even with no power. The TCU, for example, can take several hours to reset.

I prefer using FORScan to force a reset of the module. For me it’s faster and easier than pulling the fuse.

 

[JEB]

BTW I was sure I read that the hybrid traction battery helped keep up the main 12volt battery. We know there is no alternator so something has to be responsible for charging the 12v upfront and under rear seat batteries.

When I push the start button my truck usually just turns on. Engine not running. Then when called for the traction motor starts the engine. I think I have only heard the mechanical starter engage to start the engine.
So what's going on?

It’s true that the hybrid side of the Powerboost recharges the 12v battery via the DCDC converter, but that is the only place where the high voltage and low voltage systems are connected. The hybrid system does not provide starting voltage directly to the motor. In fact, the hybrid system isn’t engaged at all until the truck is put into and left in KOER (key on engine running) state. Try it. If you just turned on the ignition by pressing the start button without stepping on the brake (KOEO—key on engine off) you can’t run your generator.

Because the hybrid system isn’t engaged until the truck is fully powered up, what you are seeing when you just press the ignition button (KOEO) is the 12v starter battery providing system power—just like any other non-hybrid vehicle. And you can drain that starter just like you can with any other truck if you leave it like that without fully powering up (starting) the truck.

 

[IDK_PB]

For about a month, the message "Trailer Brake System Fault See owners manual" would flash on then off so quickly that I could not read what it said. My truck did not come with an owners manual and there isn't one on the Fordpass app. When I log in to Ford to find it, I get 5 different XLT PB manuals, none exactly for my truck. Not having a manual is almost as frustrating as the alert going off over and over and over and over...
During the holidays the alert was constant, I believe it stopped when the weather dried up ...right before I took it in.
See photo for report/replace.

UPDATE: The replacement of part did not affect the alert. About 50 miles later the alert sounded every few split-seconds... for 40 miles. It sporadically reappears and cannot be dismissed... but automatically comes on and off, repeatedly, fast and often.

 

[Snakebitten]

The DC/DC converter (digital alternator) IS supplying 12V current to the low voltage bus when the Powerboost is in accessory mode.

 

[Spiffy]

OK I'm up to speed on everything you both explained. I'm confused still about how the motor starts when I fully power up the truck. "Foot on break and hit start button " usually it just powers up , ready light and motor nit running.
Then after a bit the motor starts. That's where I believe the traction motor spins up the ice. Is that right? Like I said I have only experienced the hearing the normal mechanical starter once.
What conditions require the engagement of the starter?
My truck is FINELY getting the exhaust heat exchanger replaced tomorrow. I'm hesitant to have these guys mess with anything else. Like the trailer module.
Two weeks ago I brought it in for diagnosis.
I have an openpilot system. I unplugged everything and hid the harness CLEAR up inside dash. When I picked up the truck all the cables and harness was pulled down and left hanging by brake peddle. They damaged a cable and openpilot didn't work. Nothing was said or asked.
JEB gave me an idea to try reseting the trailer module tonight with forscan. I'm considering using FDRS to see if there is a update on it. I don't trust them to fix the current issues without having to explain my addons. I'm not familiar enough with FDRS enough to do diagnostic on it. Maybe a bit of advice?

You have to be a bit of a technician to own one if these trucks. I absolutely love this truck and I feel you all have each other's back. I can be mad at these gremlins or accept them and learn to fix.
Ha ha I had bricked it a month ago and Jesse came and rescued me.

BTW snakebitten openpilot is the shits. I know your on the fence. It's so cool despite some of current experimental stuff. And I know you like cool stuff?
As a Bluecruise replacement it's perfect. Using it without playing around with the stuff they are aggressively working on it's great. I use their lane keeping and keep ford's ACC. On both hiways and interstate it's flawless. Not a chance I'm going to buy a bluecruse subscription.

 

[JEB]

The DC/DC converter (digital alternator) IS supplying 12V current to the low voltage bus when the Powerboost is in accessory mode.

Couldn’t be very much. Otherwise, it would take a long time to drain the starter, deep sleeps would be a lot more rare and you probably wouldn’t need an aux battery.

 

[JEB]

OK I'm up to speed on everything you both explained. I'm confused still about how the motor starts when I fully power up the truck. "Foot on break and hit start button " usually it just powers up , ready light and motor nit running.
Then after a bit the motor starts. That's where I believe the traction motor spins up the ice. Is that right? Like I said I have only experienced the hearing the normal mechanical starter once.
What conditions require the engagement of the starter?
My truck is FINELY getting the exhaust heat exchanger replaced tomorrow. I'm hesitant to have these guys mess with anything else. Like the trailer module.
Two weeks ago I brought it in for diagnosis.
I have an openpilot system. I unplugged everything and hid the harness CLEAR up inside dash. When I picked up the truck all the cables and harness was pulled down and left hanging by brake peddle. They damaged a cable and openpilot didn't work. Nothing was said or asked.
JEB gave me an idea to try reseting the trailer module tonight with forscan. I'm considering using FDRS to see if there is a update on it. I don't trust them to fix the current issues without having to explain my addons. I'm not familiar enough with FDRS enough to do diagnostic on it. Maybe a bit of advice?

You have to be a bit of a technician to own one if these trucks. I absolutely love this truck and I feel you all have each other's back. I can be mad at these gremlins or accept them and learn to fix.
Ha ha I had bricked it a month ago and Jesse came and rescued me.

BTW snakebitten openpilot is the shits. I know your on the fence. It's so cool despite some of current experimental stuff. And I know you like cool stuff?
As a Bluecruise replacement it's perfect. Using it without playing around with the stuff they are aggressively working on it's great. I use their lane keeping and keep ford's ACC. On both hiways and interstate it's flawless. Not a chance I'm going to buy a bluecruse subscription.

Ford issued a recall on the trailer brake module software last year. If you don’t have an open recall notice on your truck, I doubt out of date software is your issue. But, it’s worth checking. Check the strategy of the TRM using FORScan. If it ends in -BB, the software is up to date.

As for you understanding of the hybrid system, I’m not sure what the confusion is. If you fully start the truck, everything starts up, including the hybrid system and the motor. It’s just like any other truck in that regard. The starter battery starts the motor and brings up the hybrid system, and, once on line and running, the hybrid system recharges the starter battery through the DCDC converter. The hybrid system doesn’t start the truck or supply 12V power directly to the low voltage system. It just supplies a recharge current to the starter battery.

 

[Snakebitten]

Couldn’t be very much. Otherwise, it would take a long time to drain the starter, deep sleeps would be a lot more rare and you probably wouldn’t need an aux battery.

It depends on the SOC of the High Voltage battery. If it's in the range that the algorithm allows for full functionality, the DC/DC converter supplies nearly the same voltage and current as it does in "Ready" mode.

This is accessory mode during the 2-step Powerboost starting procedure:
The DC/DC converter is drawing enough current from the HV battery to supply 57Amps of 13V current. 31A of which is beyond what the truck's 12V system is consuming, which I describe as charging current for the 12V batteries

Also note that while in Ready mode, the PCM will start ICE, to prevent the SOC from dropping much below 42%. But in accessory mode it will tolerate drawing the HV battery down considerably below that same threshold.

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