Added Factory Trailer Brake Controller to 24' Flash

[TylerEggs]

Hey everyone,

I've been reading the forums here for some time and finally got around to adding the brake controller to my 2024 Flash trim. My truck came with no listed towing packages, but it did come with the trailer backup "assist" knob.

After reading, I decided I'd start with just trying to add the Trailer Brake Controller in the dash (ML3Z-14529-AC) which ran me about $75USD. So, I popped it in (and I should mention I'm decently proficient with Forscan) and opened up the module and enabled Trailer Brake Controller and a couple other ones (there's three bunched together). For the record, the black box under the dash at the time was the factory one (ML3T-19J295-GA).

What happened after is kinda what I expected, which was basically nothing. The towing screen would show the gain adjustment level, but the buttons on the controller wouldn't do a thing. So, my next step was to order the module that goes under the dash. I popped onto eBay and bought a used one that I believed had the correct guts to actually control the trailer brakes (MU5T-19J295-HJ) and I got that for $64USD. It showed up, two harnesses to swap and a quick 30 seconds later the new one was in. I tried the brake controller....still nothing.

The key was changing the values associated to the attachment below. I can't remember who posted it, but it is pure gold when it comes to enabling this correctly.

I made the changes the highlighted values and the trailer brake controller came to life. I've tested and verified with a travel trailer that it now works. $140USD instead of $240 USD for the "Kit" (RL3Z-19H332-AA).

Hopefully this helps !

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[TreatYoSelf]

Thanks for sharing! I think adding this to my '24 Lariat would be nice.
I don't have Forscan, but I've used similar software for Volkswagen and BMW. @TylerEggs Forscan's website says that 2024 models are not supported. I've been putting off Forscan because of this, but clearly it's working with your '24 Flash. How did you get Forscan working on an "unsupported" model?

 

[Paulb55]

I havent used tried to add the trailer brake, but I have a 24 lariat and forscan worked no issues.

 

[TylerEggs]

Thanks for sharing! I think adding this to my '24 Lariat would be nice.
I don't have Forscan, but I've used similar software for Volkswagen and BMW. @TylerEggs Forscan's website says that 2024 models are not supported. I've been putting off Forscan because of this, but clearly it's working with your '24 Flash. How did you get Forscan working on an "unsupported" model?

I didn’t realize that FORScan even said it wasn’t able to work with 24’s. I’ve had zero issues with it on my 24’ Lightning and 24’ ICE F150s. I use it the same way I’ve always used it, just plug and play.

If you’re comfortable with other technology, FORScan is pretty user friendly with lots of tutorials out there.

 

[bmwhitetx]

I made the changes the highlighted values and the trailer brake controller came to life.

I see a couple of possible issues with your highlighted changes. Did you consider the current setting and just change the bit or did you just paste in a value that some other vehicle used?

The reason I ask is you have values that don't exist on any Lightning. I have created a database of over 50 Lightnings for every year, trim and most options - and some of your values are unique.

My concern is you may have disabled a feature that you should not have.

720-07-01 xxxx x*xx xx--
Lightnings with Tow have an "A" and without have a "2". Your "8" has disabled the Digital Gauge Interface.
If you had a "2" before, you should have "A" now to enable TBC.

791-01-02 xxxx x*--
For 2024, trucks with MaxTow have "5" and without have a "4". Pros have a "0".
Your "1" has disabled the PSCM.
If you had a"4" before, you should have a "5" now to enable TBM.

The rest look plausible and match other Lightnings.

 

[TylerEggs]

I see a couple of possible issues with your highlighted changes. Did you consider the current setting and just change the bit or did you just paste in a value that some other vehicle used?

The reason I ask is you have values that don't exist on any Lightning. I have created a database of over 50 Lightnings for every year, trim and most options - and some of your values are unique.

My concern is you may have disabled a feature that you should not have.

720-07-01 xxxx x*xx xx--
Lightnings with Tow have an "A" and without have a "2". Your "8" has disabled the Digital Gauge Interface.
If you had a "2" before, you should have "A" now to enable TBC.

791-01-02 xxxx x*--
For 2024, trucks with MaxTow have "5" and without have a "4". Pros have a "0".
Your "1" has disabled the PSCM.
If you had a"4" before, you should have a "5" now to enable TBM.

The rest look plausible and match other Lightnings.

for my 791-01-02 line, my as built data matched that of a Pro, where the value in the * spot was a 0.

as for my 720-07-01 line, I’ll have to dig back and see what the as built value was.

as far as things go, there have been no error codes and the controller works flawlessly. I’m definitely interested in what you’ve mentioned though. As mine is a “flash” and not a “pro”, do you think that there might be hope for the “pro” owners out there if these values work ? Just based on that 791 line to start.

 

[bmwhitetx]

for my 791-01-02 line, my as built data matched that of a Pro, where the value in the * spot was a 0.

as for my 720-07-01 line, I’ll have to dig back and see what the as built value was.

as far as things go, there have been no error codes and the controller works flawlessly. I’m definitely interested in what you’ve mentioned though. As mine is a “flash” and not a “pro”, do you think that there might be hope for the “pro” owners out there if these values work ? Just based on that 791 line to start.

I have not been keeping up with all the mods - it seems that 2024's have had more things to do with these mods like adding wires.

It's odd that your As-Built had a 0 there. The '22 and '23 trucks had either a "0" or "5" matching what you see. Not sure why the "4" option appeared just for 2024. Did you have a real early build 2024?

Here is my database of just 2024's. Byte 6 is highlighted in red. Green are check digits which can be ignored. I realize I don't have the MaxTow package broken out. Will look into that - maybe that's the missing link.

 

[TylerEggs]

If it helps, here’s my window sticker. Looks like my truck was an August of 2024 build. Prices are in CDN lol.

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