canbus layout

[RomeoZulu]

Hello all
My new 4666.6Km one month in service Powerboost xlt max tow is affected by the trailer brake power fault issue. (Who isn't)?
Dealer service confirmed a replacement of the module was required based on guided trouble shooting.
Numerous modules lodged "U" type communication type faults and I see intermittent trailer brake module power fault in the instrument cluster.
Fast forward to Jan 2 2024, when dealer service 'replaced' the module, calling it fixed after replacement and road test with no more codes noted.
Today, on an excursion for gas and a few Costco items, the familiar ping and an unreadable message flash occured twice.

Is there a downloadable image of canbus architecture for the 2023 F150 Powerboost with maxtow available
I am trying to big picture how GWMa, BCMc, BCM and TRM relate to each other.

I am paying for a towing vehicle that I am not willing to trust towing a trailer as I think brake logic, abs logic, steering logic may be different dependent on whether trailers are connected or not...

Thanks in advance RZ

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[Buyer2021]

Though I'm sure not exactly what you seek, attached are two sections from the 2022 WSM (Workshop Manual) which address trailer lighting and trailer braking systems with some semblance of a 'system diagram' including digital bus linkages between pertinent modules with some text discussion of same.

(In 417-01 you must scroll to the very end of the section)

Just offering FYI / FWIW, good luck!

BTW, in the WSM there is no single overall 'view / discussion' of the digital bus systems, to the extent that is addressed it's in the many separate sub-system sections similar to those I've attached.

 

[nitrobass24]

Might want to grab a laptop and FORScan to see what codes you really have. Sometimes these communication errors can be caused by low 12v SOC.

Make sure your battery is good and charged up, clear the codes and see if it happens again is what I would do.

 

[RomeoZulu]

Though I'm sure not exactly what you seek, attached are two sections from the 2022 WSM (Workshop Manual) which address trailer lighting and trailer braking systems with some semblance of a 'system diagram' including digital bus linkages between pertinent modules with some text discussion of same.

(In 417-01 you must scroll to the very end of the section)

Just offering FYI / FWIW, good luck!

BTW, in the WSM there is no single overall 'view / discussion' of the digital bus systems, to the extent that is addressed it's in the many separate sub-system sections similar to those I've attached.

I'm trying to determine if 'U' codes occur on the same data bus pair of wires (difficult without wiring diagram) so trying to picture the bus architecture.

 

[RomeoZulu]

Might want to grab a laptop and FORScan to see what codes you really have. Sometimes these communication errors can be caused by low 12v SOC.

Make sure your battery is good and charged up, clear the codes and see if it happens again is what I would do.

I noticed a noisy 12v trace using Forscan when I was poking around the TRM module.
It could be a bad connection somewhere in the module power circuit, a loose ground for that module, or noisy switching from battery supplied power to generator supplied power.

Another logging session may be in order. Forscan is new to me, so it like the powerboost is a steep learning curve, especially without having system information at hand.

 

[TooDah-Tex1]

You are not alone My trailer brake fault have been a problem since 6.1 update and is now at a second Dealership with a Ford Tech Helping to resolve it but nothing of yet since January 2nd will post if and when I get it resolved.

 

[RomeoZulu]

Might want to grab a laptop and FORScan to see what codes you really have. Sometimes these communication errors can be caused by low 12v SOC.

Make sure your battery is good and charged up, clear the codes and see if it happens again is what I would do.

I'll attach a text file with faults. I suspect the TRM will trigger faults when BCM loses communication with the TRM. The TRM can't communicate if its power source turns off or spikes off for some obscure reason. Surely Ford engineering and vendor (TRM) engineering have some idea about what is going on. I'm learning Forscan capabilities ie can I record power voltage over time. Touble isthat I need to have the time to figure out how to log and what to log, if Forscan even has that capability.

 

[nitrobass24]

Communication errors happen a lot on these trucks. I’d clear your codes as a first step and see if the error persist.

otherwise you might just be chasing a ghost.

 

[RomeoZulu]

Faults sure do occur frequently...to use that fact as excusable for faults exsisting is well troubling.
The fact that they do occur in a module I expect to be trouble free to tow my trailer is troubling. After multiple clearings, the same module(s) are flagging same codes. These codes may be ghostly but they point to a power delivery issue, not a module issue. How else can one explain that the very same codes appear in a brand spanking newly installed TRM?
Ensuring the batteries are properly charged, fuses properly seated in their sockets are easily checked and have been ruled out.
Maybe the monitoring capabilities built into digital technology are way to sensitive.
Maybe loss of communication (intermittent im my trucks case) could be concidered as nucance faults.
Maybe the 12 V electrical system in these Powerboost trucks and how the power is managed needs a tweak or three to provide better stability?

If the power is removed from the module it is entirely posible the module is serviceable, but the BCM, the BCMC can't communicate with the TRM and repeatedly flag lost communication. Power is required for the modules to communicate.
As I have a little experience (enough to understand power is the key) dealing with these kinds of issues, maybe code guided troubleshooting is flawed.
As background, The FixitagainTony I once owned, had many "U" communication faults the dealer service department continually blew off and never fixed. That car never delivered on its promises...
I'll have to ask the service manager how they plan to procede now that the replaced module is doing the same thing(s) I had them work to resolve.
The techs doing the work are reporting with healthy and creative beautifull speech but saying absolutely nothing in their reports. I expect better.

 

[RomeoZulu]

Though I'm sure not exactly what you seek, attached are two sections from the 2022 WSM (Workshop Manual) which address trailer lighting and trailer braking systems with some semblance of a 'system diagram' including digital bus linkages between pertinent modules with some text discussion of same.

(In 417-01 you must scroll to the very end of the section)

Just offering FYI / FWIW, good luck!

BTW, in the WSM there is no single overall 'view / discussion' of the digital bus systems, to the extent that is addressed it's in the many separate sub-system sections similar to those I've attached.

This is great information that is way beyond the operator level. As a technician, this is what I am looking for.

To test a theory, I set up a log session in Forscan to monitor module input power. The log ran for 650 seconds and stopped. It stopped long before I completed a 45 minute drive and have not had a chance to see the data recorded in 650 seconds.
Update to follow

 

[Snakebitten]

The DTC library for a fully equipped Gen14 truck is daunting. Or stunning might be a better description?

The master list of DTC is 600 pages in the 18,000 page service manual for the Powerboost.
600 pages!

It's no surprise to me that there are potential DTCs logged that are basically inconsequential from the drivers point of view.

For perspective, this is page 1 of 600

 

[RomeoZulu]

The DTC library for a fully equipped Gen14 truck is daunting. Or stunning might be a better description?

The master list of DTC is 600 pages in the 18,000 page service manual for the Powerboost.
600 pages!

It's no surprise to me that there are potential DTCs logged that are basically inconsequential from the drivers point of view.

For perspective, this is page 1 of 600

Um yeah daunting. I'm having difficulty reconciling the size of the universe...600 pages is a very close second! Must have been generated using AI!

 

[Buyer2021]

This is great information that is way beyond the operator level. As a technician, this is what I am looking for.

To test a theory, I set up a log session in Forscan to monitor module input power. The log ran for 650 seconds and stopped. It stopped long before I completed a 45 minute drive and have not had a chance to see the data recorded in 650 seconds.
Update to follow

Glad to be of some small help (if it was) - you're playing waaay above my pay-grade

Have Fun!

 

[RomeoZulu]

Glad to be of some small help - you're playing waaay above my pay-grade

Have Fun!

It's way above my pay grade too. I'm known to overthink everything like this.
But to solve this, some thinking and some guessing will be required. Digital tech has no gray area's only black and white. This requires the analytic kind I'm not gifted with. I used to unit jerk solutions as directed by the higher pay grade...

 

[Ajzride]

Its a bit pricy, but you could buy a Comma3X. One of its many functions is that it logs every signal on the canbus network the entire time you are driving.

probably wouldn’t have much trouble selling it when you are done.

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