Cold Weather Is Killing the Old HVBJBs

[Js1tr3]

Never mind; upon further reflection, the dealer decided that the 12V was the culprit after all.

Mine said the same thing, then it died again immediately. so now they are doing the HVBJB.

Sponsored

 

[ECHARGD]

That's what I'm talking about...

My dealership is telling me its because there are so many updates to so many modules that caused the failure, AND these updates can't be done OTA. They want $600 for updates that will only prove that's not the problem. Ford Customer Advocacy has opened a case.

 

[Mach-Lee]

If anyone isn't sure if their HVBJB has failed (or if it's the 12V), send me your VIN and a description of the issue in a direct message. I can try to check.

NOTE: If your car is stuck with 'Stop safely now' and won't move, then I can't see your codes.

 

[phil]

The cold weather tends to make the contactors stick more.

Does this also apply to newer versions of the HVBJB? To a smaller extent, hopefully?

 

[Mach-Lee]

Does this also apply to newer versions of the HVBJB? To a smaller extent, hopefully?

Yes, if they become damaged they will also be more likely to stick in cold weather.

 

[UN1075]

Man this worries me. I just purchased my used 21 RWD Premium Extended a few weeks ago and I keep seeing these posts now. My VIN shows no active recalls and CarFax doesn't show any work like that was done on the vehicle but I'm so worried I'll run into this problem.

If there's no recalls, what are the odds this will effect my vehicle?

 

[MoonRiver]

Man this worries me. I just purchased my used 21 RWD Premium Extended a few weeks ago and I keep seeing these posts now. My VIN shows no active recalls and CarFax doesn't show any work like that was done on the vehicle but I'm so worried I'll run into this problem.

If there's no recalls, what are the odds this will effect my vehicle?

I guess your VIN shown no recalls no dealer will voluntarily replace it for you until it breaks. All you can do is to hope it breaks before its warranty expires or it never breaks.

 

[russellholman]

I am in the same position as UN1075, I just purchased at 2021 Premium AWD. Is this covered under the 8 year battery warranty?

 

[Mach-Lee]

I am in the same position as UN1075, I just purchased at 2021 Premium AWD. Is this covered under the 8 year battery warranty?

Yes.

 

[ECHARGD]

Do ALL of the DTCs listed in the TSB 24-2163 need to have been thrown or ANY of them listed?
There is a long list and then "and/or" for the last one. I'm expecting my difficult dealership to take this position...
https://dot.report/bulletins/11000757

 

[Shayne]

As a materials engineer (though admittedly mostly semiconductors, not metals), I'm a bit puzzled. There have been discussions elsewhere about Ford under-engineering the heat dissipation in the junction box. And this fits with the fact that the conductivity of metals decreases with temperature, meaning that you want good heat dissipation for good current flow through the metal contacts. The moral of this part of the story is higher temperatures = worse.

The other factor, which I'm guessing must be in play here, is contact resistance. Contact resistance does go the other direction with temperature IF you have highly oxidation-prone surfaces. But in general this is very well known and engineers design contacts with oxidation-resistant surfaces or coatings. I would expect that, if the contacts were at all properly engineered, the surely better conductivity of the metals at low temp would outweigh the possible increase in contact resistance. Did Ford really fail to engineer for the contact resistance factor completely?

(Just adding: could I be missing an important factor? The only thing that comes to mind is a much higher current draw through the contacts at low temps. I can't think of a reason the e-motors would draw that much more, and the colder it gets the more the batteries will struggle to even provide more current. Maybe I'm missing another factor?)

This is what happened to me when I got it in February 2021 got cold and the 12V died. Contact stuck open. Two types stuck close (welded during drive/charge) or stuck open (dead 12V sitting there). Ford installed software initially and it warmed up so no problems until fall 2021 when it starts again when it gets cold. Contact stuck open 12V dead. Replaced the HVJB and the 12V has been OK since (2+ winters).

I would assume a dead 12V could simulate the same problem. If it is dead/frozen it can not close the contacts. They will stick open more with less power across them and higher resistance. I would think at a certain SOC the 12V will not close the contacts at all. Chicken and the egg but the HVJB is a historic problem. Just change the 12V every 3 years.

Agree with getting the HVJB recall done. It was a problem with this car and for 75% it appears it still is. Just shows electronics effect all differently and not every IC is created equal. Mine may have been out of the box but I did want to know how it handles its power including at 100 mph.

How many people have not got the charging port melting CSP or the back brakes locking on CSP?

 

[Murse-In-Airy]

I got a false positive SVS back on October, on our first cold snap. Then a complete fail in early January when it was really cold. This isn’t my original HVBJB but an early replacement so perhaps not an updated part. Based on the amount of jail bars I see when it’s come, I’m not surprised that the HVBJB is under duress in the low temps.

 

[fixed]

Mine just died today! Rochester NY, not even THAT cold...in the teens Fahrenheit.

 

[phil]

Do ALL of the DTCs listed in the TSB 24-2163 need to have been thrown or ANY of them listed?
There is a long list and then "and/or" for the last one. I'm expecting my difficult dealership to take this position...
https://dot.report/bulletins/11000757

Just one. Any one. "and/or" is very clear; a dealer demanding more would not have a leg to stand on.

 

[RickMachE]

Given that 2024s have had failed HVBJBs, I remain unconvinced that Ford has solved this problem. Lightnings don't seem to have any failures.

I wouldn't buy another Mach-E without assurances from Ford that they have a part that isn't prone to failure. Just returned from a 3,800 mile trip with our Lightning. Took the Mach-E to Florida and back in December, and I kept waiting to see the warning pop up...

Sponsored