Safety Recall 22S41 - 2021-2022 Mach E - HVBJB Recall [high voltage battery main contactors may overheat]

[Blue highway]

This software “work around” is a Band-Aid fix. As a GTPE owner who is already dealing with the 5 second power limiter on a performance vehicle, now we implement more limits? Someone didn’t do their job which means we go back to the DFMEA and find a part that won’t melt down!

2 second rule I suspect the new part numbers are "robust" we will see.

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[buzznwood]

Yes, if you do repeated 0-60 at WOT, you may see this condition. Like, for instance, a dealer demo unit level of 0-60 events.

0-60 events lol, the party piece that is touted for any BEV is the 0-60 and even appears heavily in the marketing if it is not built for it then don't advertise it. If Ford engineering testing was based around driving miss daisy then it has failed.

 

[voxel]

Assuming you can measure resistance in the circuit with the BECM or SBCM or what have you, that can be tied directly to temperature. Meaning, resistance varies very predictably based on temperature. So reacting to that should be doable. How it affects performance will be very interesting. It may be largely imperceptible, or maybe not.

My assumption (just as guess) would be to measure the voltage drop as motors spin faster (draw more current). A larger than expected drop would mean higher than expected resistance. Whether that is directly from the contactors or another part or even the battery is a guess with that method.

 

[Socalsp3]

This stated in the NHTSA document.

Description of the Cause : The design and part-to-part variation of the high voltage battery contactor is not robust to the heat generated during DC fast charging and multiple wide open pedal events.

Not Robust? Obviously a design flaw. When the software detects a resistance change power will be reduced. Has some small level of damage occurred during this event? Is it cumulative? I expect eventual failures of the HVBJB. Better have an extended warranty on hand.

sounds like poor design and a software update is a temporary fix to slow down rate of failure until they have enough parts/man power to replace all the vehicles. the software update will likely neuter performance and DCFC

 

[fpasta]

I really care about this recall, but by god this must be the most entertaining yet informative thread to read .

I have learned so much about EV than I ever knew I would. ?.

 

[agoldman]

So, if this all can be fixed with a software update, what's the point of the new part number HVBJB? And why can't that software be pushed immediately if it's good enough to ship in the Mach-Es currently coming off the line? Especially considering the failure can be a safety issue. It doesn't add up to me. I'm still betting the software is a band-aid.

maybe the part number is for out and out failures related to this, if and and when sort of thing..

 

[Blue highway]

I'm going to respectfully disagree. I think the WOT, (wide open throttle), condition that a lot of GT, (and others), owners do will cause the situation described. A software update would detect this and "throttle back" the demand for WTO.

I think you are right. For better or worse, when the OTA's go out we will see the extent of the limiting.

 

[buzznwood]

Hey, @moparguy, not aiming this comment directly at you but at all the GT guys who seem to be complaining like a power reduction hurts them more.
Why do you all think that?

I mean I bought an ER AWD because I simply could not justify the added expense of the GT models. I already am probably going to get a ticket with my car's acceleration. I still want to get the full acceleration I thought I'd bought. But, a potential reduction in power output will affect all of us potentially.

And, a bigger concern which might have more of an affect on me would be DCFC speeds. If this new software limits the charge rate, my road trip next month might go from 7 hours of charging round trip to 14 if they cut the rates in half. Maybe it will even be worse. And this is something ALL of us might experience GT or not.

The GT / GTPE already has serious power limitation imposed on them, which was never disclosed prior to anyone actually getting one. The concern for most will probably be that if any quick fix imposes a further limitation.

Once you get up to free way speed the limitations are very obvious where depending on circumstances you can easily get at most a few seconds of full power before the power bar turns solid grey seriously limiting performance and have to wait on a cool down timer for the bar to clear.

 

[hawkeye3point1]

Wonder if we can already see the contractor temp in OBDII?

Just a guess, but I doubt the current HVBJB has a way to measure contactor temp., and I do not recall anything in Carscanner that relates to that. It may be possible to extrapolate resistance and calculate temp. by comparing BECM sensed voltage vs. SOBDM sensed voltage, with the difference being the voltage drop across the contactor. The higher that voltage, the higher the resistance, and the higher the temp..

Assuming you can measure resistance in the circuit with the BECM or SBCM or what have you, that can be tied directly to temperature. Meaning, resistance varies very predictably based on temperature. So reacting to that should be doable. How it affects performance will be very interesting. It may be largely imperceptible, or maybe not.

My guess is that the S/W updates will be part one of the fix as theorized above and an upgraded HVBJB will provide more durable contactors and maybe sensors for resistance and/or temp..
Guessing HVBJB replacement will only be indicated if S/W metrics point to increased contactor resistance.

 

[scoopman]

Don’t kid yourself I knew a guy who routinely cooked food in his car engine here’s a list of all the delicious foods you can make inside your ICE engine
Jes Sayin

https://www.wikihow.com/Cook-Food-on-Your-Car's-Engine?amp=1

Just think of what you could cook on a fully warmed up HVBJB!

 

[Quethas]

I really care about this recall, but by god this must be the most entertaining yet informative thread to read .

I have learned so much about EV than I ever knew I would. ?.

lol. I would heavily scrutinize anything you "learn" from this thread. The volume-to-knowledge ratio here is pretty high.

 

[scoopman]

Agreed. I’ve posted many comments referencing the 1999 Cobra class action suit and resulting fixes. If the 5 second rule didn’t push GT owners over the edge in significant enough numbers, this sure has the potential to.

This case seems pretty relevant here: https://electrek.co/2021/07/30/tesla-agrees-pay-owners-battery-throttling-class-action-lawsuit/

 

[sgriffin130]

This describe me 100% I also enjoy driving my car, I make it fun for me and safe for other, definitley didn't spend $74k to drive it the same way I drive our Prius! otherwise I can keep using the Prius for grocery, this is something those guys with boring Selects won't understand, same as those owners who brag about 330 miles range on a GT!

We bought the right car that fit us, but it looks like Ford failed to make the Mach E GT trustworthy of the GT emblem that it's holding.

I have owned sport cars most of my life, as well, corvettes, Z3, etc.(not a sports car but also a 409 back in the day) so I understand what you are saying. But now I am about to become one of those guys who owns one of those BORING Selects. Rest assured, though, if I see you stranded by the side of the road I won't insult you by stopping to give you a ride in my BORING Select(comfort/technology package, tho)

 

[fpasta]

lol. I would heavily scrutinize anything you "learn" from this thread. The volume-to-knowledge ratio here is pretty high.

What I think I learned is in the forum as a whole to clarify. Not this particular thread. Ever since I got the car, I've been learning alot about EVs and batteries.

 

[Socalsp3]

If 286 warranty claims have been made out of approximately 50,000 vehicles, that’s a failure rate of 0.5%.

so far. failure will increase over time

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