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

[wvabeer]

I use a brake buddy. sensitivity is set properly. even when the brake buddy is set to max power and sensitivity, there is no way the brake buddy can cause a lockup if the EBB is off. If the EBB comes on, it will cause a lock up. I probably used/tested the brakes 50 times and it worked perfectly, but something happened before approaching the toll both that turned on the EBB which caused a lock up.

I use the brake buddy too. I've never had it change.

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[cwik]

I use the brake buddy too. I've never had it change.

I should add that I had no issues before the update when I was pulling fuses every time. For me, the 5 minutes of waiting is annoying but much preferred to worrying about if the there will be a lock up every time I brake.

 

[Bob Britton]

I use a brake buddy. sensitivity is set properly. even when the brake buddy is set to max power and sensitivity, there is no way the brake buddy can cause a lockup if the EBB is off. If the EBB comes on, it will cause a lock up. I probably used/tested the brakes 50 times and it worked perfectly, but something happened before approaching the toll both that turned on the EBB which caused a lock up.

Your right, something changed and my guess is that it has nothing to do with your Brake Buddy setup. Sometimes while my Bronco is parked in the garage many hours after being driven it will suddenly start a series of relays clicking. I've even had this happen after being parked overnight, it's odd and I have know idea what sets it off "wakes it up" ?
I wonder if this is what's happening with your Bronco while towing, waking up the EBB?

 

[wvabeer]

I use the brake buddy too. I've never had it change.

I should add that I had no issues before the update when I was pulling fuses every time. For me, the 5 minutes of waiting is annoying but much preferred to worrying about if the there will be a lock up every time I brake.

So when you pulled over the brakes woke-up?

 

[Jmor]

I wonder if an accidental key fob button could have activated it when pressed.
What do You think @grtharris ?

 

[Bob Britton]

With the new update, using key fob should not have any effect on flat tow mode.

 

[wvabeer]

I wonder if the battery got low and caused it.

 

[grtharris]

When I was testing after the download, I tried the key fob and also locking and unlocking from inside the Bronco to see if it would reset the EBB and it did not.
In hindsight I would like to know if cwik noticed if he was getting the "IN TOW MODE ALARM" when he opened the Bronco door, something for all of us to pay a little more attention to for from now on when we get ready to disconnect from the motorhome.
Hopefully I will be getting our motorhome back next week. So there will be a short 60 mile tow when I pick it up and then a 500 mile trip later in May.

 

[cwik]

Honestly I was hoping to get some feedback from @grtharris

after the update, during my stationary tests, I constantly saw the “neutral tow mode enabled message” every time I opened the door. key fob presses did not turn on the EBB, the update seemed to work.

during my driving tests, the “neutral tow mode enabled“ message was always there, every time I stopped and opened bronco the door. even after the lock up, I pulled over a couple miles down the road and the “neutral tow mode enabled” message was still there. I took it out of neutral tow mode, and enabled it again while pulling the fuses (pre-update style). I have a charge line running to a battery charger on the bronco, so voltage was good.

I was thinking about the timing some more. in prep for the 700 mile trip, I had hooked up the bronco the night before, put it in neutral tow mode, and drove the RV a few miles to test it, brakes worked fine. I left it hooked up in neutral tow mode overnight for an early AM departure. In the morning I checked everything again, “neutral tow mode enabled“ message still showed, and the brakes still worked fine for the first couple hours. by the time the lock-up happened, it had been in neutral tow mode for maybe 10-12 hours, I didn’t time it exactly. Maybe even the with the update the EBB will wake up after 12 hours or something, thats my only guess at the moment. When I did stationary testing I only did a couple of hours, maybe I should do some overnight stationary testing.

 

[grtharris]

Honestly I was hoping to get some feedback from @grtharris

after the update, during my stationary tests, I constantly saw the “neutral tow mode enabled message” every time I opened the door. key fob presses did not turn on the EBB, the update seemed to work.

during my driving tests, the “neutral tow mode enabled“ message was always there, every time I stopped and opened bronco the door. even after the lock up, I pulled over a couple miles down the road and the “neutral tow mode enabled” message was still there. I took it out of neutral tow mode, and enabled it again while pulling the fuses (pre-update style). I have a charge line running to a battery charger on the bronco, so voltage was good.

I was thinking about the timing some more. in prep for the 700 mile trip, I had hooked up the bronco the night before, put it in neutral tow mode, and drove the RV a few miles to test it, brakes worked fine. I left it hooked up in neutral tow mode overnight for an early AM departure. In the morning I checked everything again, “neutral tow mode enabled“ message still showed, and the brakes still worked fine for the first couple hours. by the time the lock-up happened, it had been in neutral tow mode for maybe 10-12 hours, I didn’t time it exactly. Maybe even the with the update the EBB will wake up after 12 hours or something, thats my only guess at the moment. When I did stationary testing I only did a couple of hours, maybe I should do some overnight stationary testing.

I have not done any towing since the download. Our motorhome is in the shop waiting on getting a new rebuild engine. Actually got to see and touch the engine today, so should be ready to go next week.
I only did some stationary and rolling down a hill testing. This weekend I will let it set over night in Tow Mode and see if I can get the EBB to reset.

 

[Tilzbow]

Brakes shouldn’t lock with an active ABS system. So it seems EBB came back on and the ABS system was offline. Maybe ABS is decactivated when tow mode is enabled. That doesn’t make much sense though….

 

[Eric Bond Hedden]

Problem with the update?
I got the OTA update in early March. I did what i thought was a good amount of testing. I put it in Neutral tow mode as usual, without pulling fuses. I noticed the new brake warnings. I had rolled down my drivers window so I could reach the brake pedal with a 2x2 from outside. I left it parked for a couple hours, periodically visiting to test the brake pedal. It was noticeable the EBB was not active, and the brake lights did not illuminate. I pushed lock/unlock a few times during the test to see if that would wake up the EBB, it did not, everything seemed good.

In preparation for my first post-update trip I hooked up to the RV, enabled Neutral tow mode without removing the fuses, and took a drive for a few miles. Everything worked great. We left the next day, I checked the brakes several times before we got on the highway, still working great.

About 2 hours in, we approached a toll booth, I applied a reasonable amount of braking. at that point the bronco’s brakes locked up. that was NOT an enjoyable experience, it seems the EBB was activated somehow even though nothing had changed. nothing catastrophic happened but I did not want to repeat it, so I pulled over next chance I had and pulled the fuses. No issues for the rest of the 12 hour drive.

I’m going to continue pulling fuses.

Maybe you had your brake system set to sensitive.

Which fuses do you pull? (I also flat tow a 2021 OBX, and I thought the lock-up occurred because I set the brake pedal application at too sensitive a setting.)

 

[wvabeer]

Which fuses do you pull? (I also flat tow a 2021 OBX, and I thought the lock-up occurred because I set the brake pedal application at too sensitive a setting.)

 

[cwik]

yep. I was following the TSB and had no issues. after the update, I skipped the TSB steps and got a lock-up, so I went back to following the TSB and again no issues.

 

[Bob Britton]

I got the update and currently on a trip, pulled the Bronco about 1000 miles over the last week with no issues . Have not pulled any fuses but have been keeping a close eye on things , so far so good!

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