Stop Safely Now (HVBJB): Mach-E Owners Biggest Fear - Facts and Info Thread

[dbsb3233]

While I don't think everyone, or even 1% of owners, will take the MME on a track that doesn't excuse it.

It's not excusing it. Nor are they since they issued a recall. The software may just be a mitigating fix for now. We'll see.

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[Blue highway]

I'm not sure in what world "reducing battery power" and "reduce vehicle power" is not going to effect performance. It could be vehicle performance or charging performance, either is bad. Farley is just digging a bigger hole. He must have the same media team as Biden...

I'm not being negative, I'm upset because I thought they were going to do the right thing. In the IT world I couldn't go up to a customer and say, sorry your server is overheating so we will pull one of the two processors since they generate the most heat. That's not acceptable.

This software does not prevent the issue from happening completely.

I'm not sure in what world "reducing battery power" and "reduce vehicle power" is not going to effect performance. It could be vehicle performance or charging performance, either is bad. Farley is just digging a bigger hole.


This is the crux of the matter isn't it. Reducing power across the relay will reduce car performance... to save an eFing relay. It's just inescapable. Worse yet, It affects those most interested in performance the most. (the high margin GT car buyers)

You and I don't have a GT... so who cares? You will... because the MME is on the brink of becoming the Chevy Bolt. If Ford does this (SW fix to limit current instead of fixing the bad part), they are not shooting themselves in the foot... they are shooting themselves in the head.

It's ~$800 part plus labor. paying for that is bad... destroying Fords EV reputation... priceless.

we shall see...

 

[Blue highway]

I think it's masterfully worded. His statement doesn't claim the issue was detected ONLY on demo units, but it does imply that it was detected proactively before customer units (not the case, clearly). So it's not technically an incorrect statement, but its definitely downplaying the issue from an implication perspective.

so not technically incorrect... just ethically incorrect?

 

[Blue highway]

Trying to understand what this recall is all about, I had to do a little research on what a contactor does in an electric vehicle. I found a course that talks about Battery Management Systems (BMS) and how it controls the contactors located in the HVBJB

What I don’t yet understand, and I’m still digging, is how these fail from WOT events stated in the recall. I think I understand when DC Fast Charging can cause issues. It did give me an introductory view on how the BMS controls the contractors in a “Generic” EV. I have no idea what Fords BMS is doing.

(855) 1.3.6- How to control contactors with a BMS - YouTube


HVBJB (High Voltage Battery Junction Box)

• HVBJB is used to connect and disconnect the high voltage battery from the internal high-voltage BUS used for the HV vehicle systems
• Disconnecting the pack at both terminals requires two High-Current contactors
• Low voltage signals activate the contractor to open / close
• 3 Contactors are used to connect / disconnect from the HV bus
  • Positive Contactor
  • Pre-Charge Contactor
  • Negative Contactor
• You can’t close both Positive and Negative contractors simultaneously, instant high current would cause potential arching and weld the contractors closed or blow a fuse
• SO, you must use a Pre-charge Contractor to pre-charge the positive contactor before closing it
  • The Pre-charge contractor is connected to a pre-charge capacitor / resistor
  • This resistor/capacitor slows down (resistor) the instant current from the battery, charging the capacitor allowing it to prime the positive contractor so when it closes it’s already at the same current as the battery.

Startup Sequence

1. Close Negative contractor
2. Close Pre-Chargecontactor, high voltage then flows through a resistor/capacitor, which limits the voltage so the contactors don’t Arc or Weld close.
   1. You need to monitor the temperature of the Pre-charge/contractor
   2. You need to monitor the voltages so they don’t converge to quickly
3. If Temp/voltage are Good from the checks
   1. Close the Positive contactor – HVB is now connected to internal HV equipment
4. Open the Pre-Chargecontractor
   1. Note that the resistor/capacitor is still connected for the shutdown sequence

Shutdown - This is much harder to answer without know what their BMS is doing

• Option 1: Abrupt disconnect which may cause arcing/welding of contractor
• Option 2: You Could activate Pre-charge contactor utilizing the resistor/capacitor
• Option 3: Since the Pre-charge resistor/capacitor is always available and connected you don’t need option 2 because the resistor/capacitor has enough energy to safely open all contacts

Because WOT throttle events are ~900 Amps in a GT. (KW of motor / 400V ignoring motor efficiency) It doesn't take much resistance to generate a LOT of heat.

 

[buzznwood]

Sounds like what happens when the top takes another glance at the bottom line.
Their action seems to be just enough to satisfy NHTSA's safety concern while mitigating the number of warranty reworks they will have to do.

This pretty is standard MO do just enough Ford currently seems to be in an bit of an endless recall whirlwind at the moment, no manufacture has a 100% record of problem free model launches, but Fords recent track record over the past few years is not pretty.

One thing to keep an eye out for is if a TSB comes out later on in regards to customers report powerloss. As chances are it may only be the WOT & DCFC as if your life depends on it brigade that are going to notice it compared to those that are chauffeuring miss daisy and L2 only. So another potential way they can fix an additional subset of vehicles under warranty to try and keep replacement costs down. Either way it is not a good look.

 

[Scooby24]

so not technically incorrect... just ethically incorrect?

That's how I would interpret it, yes....though in the scheme of things it doesn't HURT anyone....and if I was affected by the issue I don't know that I would be upset or offended by such a statement. It's just PR.

 

[LS61303]

Got a question I am hoping the community can help me with:

I just got the call from the service center I took my car to with good news; they knocked out the HVBJB replacement as well as a few other TSB's I asked them to! Only took about 10 days, and they had certified and trained technicians diligently working on it the whole time.

Anyways, the Service Manager advised me "to not fast charge until the advanced notice fix is transitioned to a full recall and repair, and I can bring it in for the software calibration". I am wondering if anyone who has had their HVBJB replaced recently has fast charged and if its caused a whole lot of harm? I was planning on taking a trip tomorrow and will need to fast charge on the way back up.... I am guessing we have quite a few folks who have had their junction box replaced and haven't gotten the recall fix yet. If you're out there, please tell me how your fast charging has been, and if your service center advised against it after the repair. I know not to fast charge and WOT in the meantime, and I will take extra care to let the car cool down before driving after DCFC. But I will need to at least once in the foreseeable future...

 

[Logal727]

Got a question I am hoping the community can help me with:

I just got the call from the service center I took my car to with good news; they knocked out the HVBJB replacement as well as a few other TSB's I asked them to! Only took about 10 days, and they had certified and trained technicians diligently working on it the whole time.

Anyways, the Service Manager advised me "to not fast charge until the advanced notice fix is transitioned to a full recall and repair, and I can bring it in for the software calibration". I am wondering if anyone who has had their HVBJB replaced recently has fast charged and if its caused a whole lot of harm? I was planning on taking a trip tomorrow and will need to fast charge on the way back up.... I am guessing we have quite a few folks who have had their junction box replaced and haven't gotten the recall fix yet. If you're out there, please tell me how your fast charging has been, and if your service center advised against it after the repair. I know not to fast charge and WOT in the meantime, and I will take extra care to let the car cool down before driving after DCFC. But I will need to at least once in the foreseeable future...

Pretty sure it’s the combo of WOT and DCFC, not specifically DCFC on its own, good news is your dealer already knows how to do it if it happens again!

 

[mkhuffman]

Got a question I am hoping the community can help me with:

I just got the call from the service center I took my car to with good news; they knocked out the HVBJB replacement as well as a few other TSB's I asked them to! Only took about 10 days, and they had certified and trained technicians diligently working on it the whole time.

Anyways, the Service Manager advised me "to not fast charge until the advanced notice fix is transitioned to a full recall and repair, and I can bring it in for the software calibration". I am wondering if anyone who has had their HVBJB replaced recently has fast charged and if its caused a whole lot of harm? I was planning on taking a trip tomorrow and will need to fast charge on the way back up.... I am guessing we have quite a few folks who have had their junction box replaced and haven't gotten the recall fix yet. If you're out there, please tell me how your fast charging has been, and if your service center advised against it after the repair. I know not to fast charge and WOT in the meantime, and I will take extra care to let the car cool down before driving after DCFC. But I will need to at least once in the foreseeable future...

Personally I find it ridiculous they are recommending you don't DCFC. Did you get the upgraded part? If you did, you are better off than the rest of us and if you can't DCFC, then we shouldn't either. Which I think is ridiculous.

Take the trip, DCFC as you need to, and don't worry about it. That's what I would do based on what we know about the problem. In fact I am on a trip that requires DCFC right now.

And I also had a little WOT entertainment today. It does worry me, but the risk is low especially if the car is cool. If I had the upgraded part I wouldn't worry at all. Smash it!

 

[rcechinel]

Got a question I am hoping the community can help me with:

I just got the call from the service center I took my car to with good news; they knocked out the HVBJB replacement as well as a few other TSB's I asked them to! Only took about 10 days, and they had certified and trained technicians diligently working on it the whole time.

Anyways, the Service Manager advised me "to not fast charge until the advanced notice fix is transitioned to a full recall and repair, and I can bring it in for the software calibration". I am wondering if anyone who has had their HVBJB replaced recently has fast charged and if its caused a whole lot of harm? I was planning on taking a trip tomorrow and will need to fast charge on the way back up.... I am guessing we have quite a few folks who have had their junction box replaced and haven't gotten the recall fix yet. If you're out there, please tell me how your fast charging has been, and if your service center advised against it after the repair. I know not to fast charge and WOT in the meantime, and I will take extra care to let the car cool down before driving after DCFC. But I will need to at least once in the foreseeable future...

Did you get confirmation it was the new improved and mysterious part that Ford pretends it doesn't exist?

 

[breeves002]

In case anyone is interested Ford paid $2188.83 for this claim on my car. $932.20 in labor $1256.63 for the part. 6.1 hours of labor billed. 286 claims according to the NHTSA doc means this has cost Ford $600k so far + a bunch of engineering and admin time.

 

[fpasta]

In case anyone is interested Ford paid $2188.83 for this claim on my car. $932.20 in labor $1256.63 for the part. 6.1 hours of labor billed. 286 claims according to the NHTSA doc means this has cost Ford $600k so far + a bunch of engineering and admin time.

And if the rest of the 48,714 US cars get the same service done with that cost - would cost Ford about 30 Billion, right?

 

[newmme]

And if the rest of the 48,714 US cars get the same service done with that cost - would cost Ford about 30 Billion, right?

It will be way more, as Ford has more recalls currently than any other manufacturer. Not sure if the 3 million would be OTA or not though.

Ford leads all automakers with massive recalls

 

[rcechinel]

And if the rest of the 48,714 US cars get the same service done with that cost - would cost Ford about 30 Billion, right?

Iwill take the bait, but more about $100 million.

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