Flat Tow 2.7l Electric Brake/BMS time out. NTHSA claim

[AZBronco21]

Please limit this thread to only this issue!!!!!

I own a 21 Outer Banks Sasquatch Standard bumper with a 2.7l engine. It is set up with a Blue OX base Plate, an Airforce 1 brake controller and charge line from the coach to the battery. As you may have read from another member, there is a serious safety issue relative to the Electronic Brake Booster (EBB) going to sleep after 45 min of being put in Flat tow mode. We suspect the battery management system (BMS) is sleeping the EBB. It appears that this is a programing issue and would be a relatively easy fix, if only we could get Ford to pay attention.

I have reached out to my selling dealership, they have searched for recalls and TBS's to no avail. They do not believe that the Ford diagnostic tools will allow them to change the settings. Until Ford comes out with something they did not even want to have the vehicle brought it. Next, I was contacted by Ford customer service due to a rather direct tweet I sent to @Ford. They gathered all my information and basically said it is specific to your vehicle and you need to take it to the dealership. I requested to talk to the Bronco engineering team and was told that was not possible.

Currently the only way to "solve" the issue is to do one of two things. 1. Click the lock button on the remote from the tow vehicle, in my case a 45' 51k pound motorhome. This wakes up the bronco and restarts the 45 min timer. 2. Do not complete step 8 in the flat tow mode (turn of the ignition), this leaves it on but allows miles to rack while towing. Neither of these are acceptable!

There also may be a way using Forscan to disable the BMS. I am hesitant to complete this option due to unintended consequences and possible warranty issues. Plus I am not that much of tech geek.

So, this is going to take a village to get Ford to pay attention to this issue. I intend to file a NTHSA safety claim in the next day or so. Here we can keep a log of those that have confirmed the issue and those that have and are willing to file a claim with NTHSA.

If anyone knows the email address for Eric Loeffler (Chief Bronco Engineer) please PM me.

Once again please do not clutter the thread with topics that are not specifically about this issue.

Respectfully,

JD

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[AZBronco21]

Interesting that no one else so far is having this issue. If you are flat towing a 2.7l. Please check your brake booster after 45 min.

 

[Girk66]

I have not read of any workaround available at this time for the Electronic Brake Booster (EBB) going to sleep after 45 min of being put in Flat tow mode. Applicable to 2.7l owners. I have not gotten far enough to verify this is true for me. If true, this is is not acceptable! After all the press about all new Broncos being flat towable. Anybody with reliable info on this, please post! Thx

 

[AZBronco21]

Thanks for joining the thread. I am testing mine this weekend. Grant on this site has done quite a bit of testing. I have Airforce One, which is different than Grant’s. Stay tuned, I don’t think there is any real good info or fixes yet. Ford has been very unhelpful so far.

 

[72BroncoSand]

Use the search function. There is a thread that has been discussing this for months. Many seeking the solution

 

[Tilzbow]

OP has obviously read the other thread since he identified one of the main contributors by name in their last post. Since that other thread has a lot of other topics it seems pretty obvious he’s trying to call attention to the issue on a separate thread.

If I had my Bronco I’d likely file a supporting claim.

 

[da_jokker]

I'm just curious, can someone explain to me what the issue is. Something about the break going to sleep but I don't know what that means.

Are you saying that while flat towing the brakes come on after 45 minutes?

 

[Tilzbow]

I'm just curious, can someone explain to me what the issue is. Something about the break going to sleep but I don't know what that means.

Are you saying that while flat towing the brakes come on after 45 minutes?

The electronic brake boost used with the 2.7 liter engine goes to sleep after about 45 minutes rendering your auxiliary brake system ineffective. The 2.3 liter uses vacuum boost and doesn’t have the issue.

 

[drew707]

I'm just curious, can someone explain to me what the issue is. Something about the break going to sleep but I don't know what that means.

Are you saying that while flat towing the brakes come on after 45 minutes?

No the power brakes remain active for that time period. After which they stop functioning with any boost and become unboosted, but still functional.

My friend ran into this issue, we had to use the hydroboost mode on his braking system (forget what it was) with his 2021 F-150 with EBB and let the system go to sleep before towing. Which was easy time to kill prepping other things. Otherwise when towing the brakes on the F-150 would lock up aggressively.

I agree though this needs to be addressed

 

[Girk66]

Use the search function. There is a thread that has been discussing this for months. Many seeking the solution

Tried a search, could not locate this other thread. Can you give me the link or search parameters? Thx

 

[Girk66]

Confirmed at dealership today that this is an issue that they‘ve just been made aware of by Ford. Should see more on this soon.

 

[AZBronco21]

That is excellent news, hopefully it won’t be too long

 

[72BroncoSand]

Tried a search, could not locate this other thread. Can you give me the link or search parameters? Thx

Im not very good with tech stuff. Hoping this link works. The search function on this site is difficult. Use google search and add Bronco6g in the search. Works good for me.
https://www.bronco6g.com/forum/threads/flat-tow-equipment-needed-to-flat-tow-the-2021-bronco.19759/

 

[AZBronco21]

Gkirk66, sent you a PM with my contact info. Relative to your contact with dealer.

 

[dgorsett]

Just a caution for those planning on tricking the Bronco into staying 'on' to keep boost: The procedure for disabling neutral tow involves turning on accessory mode and pressing brake, so be sure Bronco stays in tow mode when Bronco is 'on' and brake gets activated. It actually would be hard to tell since the transmission is left in neutral as well as the transfer case.

From OM:

1. With your vehicle properly secured to the tow vehicle, switch your vehicle to accessory mode by pressing the push button ignition switch without pressing any pedals. Towing Your Vehicle 2. Starting with the brake pedal released and the transmission in neutral (N), fully press and hold the brake pedal for approximately seven seconds and shift the transmission to park (P). Continue holding the brake pedal until the instrument cluster display shows 2H and Neutral Tow Disabled. Note: If completed successfully, the instrument cluster displays 2H and Neutral

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