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

[back_at_it_19]

Preface:

The purpose of this post is to bring information together so that people can reference what is known about the HVBJB issue. While some of us might know more than we are publicly talking about, for confidentiality reasons, we cannot disclose everything. I'll do my best to help calm nerves, be honest and not violate agreements in the process. All of the information below has been discussed on this forum, extracted from posted DTC's and service repair orders or gathered via non-confidential communication.

I am an MME GTPE owner myself. My vehicle is just as susceptible as any other owner. Obviously, we all have our own way of mentally dealing with things. I, personally, do not worry about this happening to me and I don't think people should worry. We don't worry about flat tires, alternators, getting in an accident etc. Being prepared and having the necessary knowledge is not only relieving to the mind, but the best and only course of action in this case, as of now.

Finally, "Stop Safely Now" is a generic message and is used for many different critical faults. This post is specifically about the failure of the High Voltage Battery Junction Box.

Other commonly referred to names:

• Cold weather issues
• LVB Battery Failure
• HVJB Failure
• BECM Failure
• High Voltage Battery Issue

The problem:

Late last year we had a few members starting to report that their cars would say "stop safely now". It was attributed by the forum members as something related to the cold as it was mostly happening to people in colder climates. Many people also attributed the issue to faulty LVB's most likely due to the fact that the MME previously had LVB issues. As time went on, a few of us attempted to reassure people that it wasn't LVBs at all. Obviously, those with repair orders, whom this affected had insight into what was happening. They received repair orders for the BECM and HVBJB. It came to light through this process and those of us with insight that it wasn't the LVB.

The LVB was often blamed early on because of the aforementioned previous issue and also because when the HVBJB fails it no longer charges the LVB. Thus, leaving the LVB to die. This is like an alternator going out in an ICE vehicle. The battery is dead, but only as a result of a bad alternator.

Many months ago, it was disclosed that temperature does play a part in the failure of the HVBJB, and that will be discussed further down.

When this happens, the driver will receive a "stop safely now" indicator followed by the car being bricked essentially. The car must be towed in and diagnostic codes will reveal that the contactors in the HVBJB are stuck, either open or closed.

In the affected vehicles, it is possible that the high voltage battery main contactors may overheat, which can result in an open contactor or welding condition. Should the contactors weld closed while driving, a powertrain malfunction warning light will be illuminated on the next drive cycle, along with a no start condition.

If the contactors open while driving, a powertrain malfunction warning light will be illuminated, the vehicle will display Stop Safely Now in the instrument panel cluster, and the vehicle will experience an immediate loss of motive power. The vehicle will coast to a stop, and all 12V systems including power brakes and steering will remain functional.

The resolution:

When this happens, the only thing you can do is have the car towed and the HVBJB replaced along with the BECM (the BECM was originally replaced at the onset of this issue, but has since been determined to not need replacing). Some people report that it took 2 days while other dealers took months.

Update 06/03/22: Ford has a new version of the HVBJB that's now being installed into problematic cars. See this post and below.

Ford has issued a recall for this problem. For some vehicles software will be used to mitigate and prevent the issue from happening and for performance vehicles the hardware will be replaced under recall.

Prevalence:

I have no numerical statistics on the prevalence. My guess is that it's less than 1%. Based on the forum self-reporting done this would coincide with my guesstimate.

Is my car immune to this:

Simple answer, no. This can happen to any MME, of any MY, in any climate, anywhere in the world built prior to May 24, 2022.

Is my car more prone to this:

GT models are far more prone to having HVBJB failure to due to higher draw of power.

Is temperature to blame:

As it was confirmed months ago on this forum by a Ford Engineer, temperature does play a role in this. It's not however, just cold and heat actually plays a larger role.

What is Ford doing:

Update: 06/03/22 - Ford is now fitting cars that have a defective HVBJB with a revised HVBJB. Further details will likely follow. See this post and below.

Ford has issued a recall for this problem. For some vehicles software will be used to mitigate and prevent the issue from happening and for performance vehicles the hardware will be replaced under recall.

Revised Part numbers:

NK4Z-10C666-A is for RWD and it replaces LK9Z-10C666-B and LK9Z-10C666-C
NK4Z-10C666-B fits both the AWD and the GT and it replaces LK9Z-10C666-A.

Thanks to @chrisGT for the RWD part number.

Will this be a recall:

Recall 22S41 is now in place.

See this post: https://www.macheforum.com/site/threads/safety-recall-22s41-2021-2022-mach-e-hvbjb-recall.18681/

What to do to prevent this from happening:

Unfortunately, there's nothing you can do, or not do, that we are 100% confident in being resolute. Because this is caused by excessive heat on the contactor driving in a style that won't cause excessive heat would be your best bet. Don't be afraid to charge the car or drive the car.

What to do in the meantime:

My personal recommendations -

• Back in to all parking spots
• Back in to the garage
• Install tow stickers (see here) (purchase here)
• Keep a tow card in the car (see here)
• Know the procedure for a dead LVB jump (refer to the manual here) - Page 267
• Know how to emergency tow the vehicle. Don't rely on the tow company. (refer to the manual here) - Page 271

If you experience "stop safely now" I would recommend -

• DO NOT attempt to start the car over and over! Save the LVB as much as possible and keep the car off
• As long as it's safe to do so, unlatch the hood but leave it shut, not latched, to keep the light off
• Roll down a window and close the door to keep the cabin lights off
• If you are at home, connect the LVB to a battery maintainer or charger
• If it were me, I would call my insurance roadside over Ford since they are much quicker, but that's up to you.
• Look to have it towed to an EV specialty dealer. They have the tools and battery lift to fix this. Ensure the dealer will accept the car before having it towed there.
• Get a case logged with Ford Immediately. Ford can put pressure on the dealer and expedite the replacement parts.

Important Ford Numbers:

Ford Roadside (to get towed):

(800) 241-3673

Ford customer support (to get a case started):

(800) 392-3673

Links to other beneficial resources:

How to tow an MME
Failure Survey
List of members with HVBJB failure
File a NHTSA complaint

Initialism used in this post:

EV = Electric Vechile
MY = Model Year
HVB = High Voltage Battery
LVB = Low Voltage Battery
MME = Mustang Mach E
SSN = Stop Safely Now
BECM = Battery Energy Control Module
GTPE = GT Performance Edition
HVBJB = High Voltage Battery Junction Box

Other resources:

The HVBJB in the MME is not a unique component to Ford. It's an essential part of EVs. Contactors getting stuck also isn't new or unique to Ford. Using Google you might be able to find other instances in other makes (like this) with little nuggets of information that might just be very similar to the MME issues. Like the above link mentions, we have also seen members get similar errors when there's an electrical short, and it's not a HVBJB failure but presents its self similarly.

In closing:

If you think I should add information to this post, let me know and I'll be more than happy to consider it and maintain this post. As more information is made public or authorized for public consumption I'll update it as well. I'm not active much more on this forum due to all the negativity and hyperbole here, but felt this post was necessary because of all the outside communication I receive from other members.

Great update with latest. Thx!

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[AKgrampy]

Hope it’s down hill

Unfortunately we have to drive through the Alaska Range to get there. Highest peak in North America, Denali, is in the Alaska Range. Nice view on a clear day!

 

[Mach-Lee]

@DevSecOps, I think you should add more to "What to do to prevent this from happening" about limiting repeated accelerations. Since this is now confirmed to be an overheating issue, it's obvious that multiple heavy accelerations in a short period would likely overheat the contactor.

I would be more specific say: limit repeated heavy accelerations, such as racing from stoplight to stoplight, or driving at very high speeds (>80 MPH?) for long periods.

 

[mwtechy]

@DevSecOps, I think you should add more to "What to do to prevent this from happening" about limiting repeated accelerations. Since this is now confirmed to be an overheating issue, it's obvious that multiple heavy accelerations in a short period would likely overheat the contactor.

I would be more specific say: limit repeated heavy accelerations, such as racing from stoplight to stoplight, or driving at very high speeds (>80 MPH?) for long periods.

I'd also be curious if the one pedal driving has anything todo with it.

 

[DevSecOps]

@DevSecOps, I think you should add more to "What to do to prevent this from happening" about limiting repeated accelerations. Since this is now confirmed to be an overheating issue, it's obvious that multiple heavy accelerations in a short period would likely overheat the contactor.

I would be more specific say: limit repeated heavy accelerations, such as racing from stoplight to stoplight, or driving at very high speeds (>80 MPH?) for long periods.

While there are likely ways to ensure failure, some of us have NDAs with Ford that specifically state that any information which can cause harm to Ford is to be considered confidential and not disclosed. I don't feel comfortable getting ahead of Ford with that information as some people might try to force failure in order to get it replaced.

Additionally, not everyone who had HVBJB failure drove in the same way. I've personally talked to many people with failure who described their driving style, all very different. Also, many, many had failure in the snow, where I would assume, they weren't driving in an aggressive manner.

Therefore, I think the appropriate avenue is to educate people on why this happens and explain how the contactor heats up. With that information people should be able to make informed decisions on how to minimize possible failure. Since there are many ways that failure occurs, some of which are just a stroke of bad luck, I don't want to be the one who says "don't do this and you'll be okay". The evidence doesn't support that it's that simple.

I think it's a wise decision to drive more conservatively until the recall is performed however 99% of owners don't experience HVBJB failure and drive the car as it's to be driven. All being said, I did elaborate a little more on that section.

 

[DevSecOps]

I'd also be curious if the one pedal driving has anything todo with it.

There's no evidence I've seen to support 1pd having any significant impact.

However, regen, in combination with other high draw events could likely exacerbate possible failure. Regen can come from braking without 1pd as well.

A lot of power flowing through the contractor will heat it up and potentially cause welding.

 

[macchiaz-o]

Unfortunately we have to drive through the Alaska Range to get there. Highest peak in North America, Denali, is in the Alaska Range. Nice view on a clear day!

This sounds like a "fortunately" to me. Also, you get to leave Fairbanks!

 

[Mach-Lee]

While there are likely ways to ensure failure, some of us have NDAs with Ford that specifically state that any information which can cause harm to Ford is to be considered confidential and not disclosed. You might not have these restrictions, but the people you learn information from might.

Additionally, not everyone who had HVBJB failure drove in the same way. I've personally talked to many people with failure who described their driving style, all very different. Also, many, many had failure in the snow, where I would assume, they weren't driving in an aggressive manner.

Therefore, I think the appropriate avenue is to educate people on why this happens and explain how the contractor heats up. With that information people should be able to make informed decisions on how to minimize possible failure. Since there are many ways that failure occurs, some of which are just a stroke of bad luck, I don't want to be the one who says "don't do this and you'll be okay". The evidence doesn't support that it's that simple.

I think it's a wise decision to drive more conservatively until the recall is performed however 99% of owners don't experience HVBJB failure and drive the car as it's to be driven. All being said, I did elaborate a little more on that section.

The acceleration thing is my own recommendation based on reading the recall and thinking what you could do to overheat it. Regardless, thanks for updating that section. There is a random component to the failures I haven't been able to explain either, so some mystery remains. Yes you can drive like grandma and still have it happen, but driving like you stole it probably increases your chances. I feel like there's some part variability at play too (like computer chips), so that's maybe why some people can drive hard without it happening.

 

[Stang68]

The acceleration thing is my own recommendation based on reading the recall and thinking what you could do to overheat it. Regardless, thanks for updating that section. There is a random component to the failures I haven't been able to explain either, so some mystery remains. Yes you can drive like grandma and still have it happen, but driving like you stole it probably increases your chances. I feel like there's some part variability at play too (like computer chips), so that's maybe why some people can drive hard without it happening.

All-in-all this is a big bummer. Half the fun of driving this car is the acceleration. Now I'm going to be babying it for the next couple of months while waiting for recall notice, dealership appointment, and parts coming in. I'm a Mach E fan through and through but this really is a damper on the ownership experience. I've had recalls before on other cars but this one really sucks because you can be stranded anywhere without any warning signs.

 

[rcechinel]

There are also cars like mine, in the shop waiting for the new and hopefully perfectly improved HVBJB. That's the hope anyway, somewhat expect the new part to arrive this week.

BTW, our other vehicle has been on a recall since Feb for potential HVB fire. Chrysler's response so far has been to park away from home and other vehicles & don't charge it. Called them Saturday for any update, nada, no fix yet, so yea, it could sort-of be worse.

Good catch, I updated my post with this scenario as well.

 

[mikeinet]

While there are likely ways to ensure failure, some of us have NDAs with Ford that specifically state that any information which can cause harm to Ford is to be considered confidential and not disclosed. I don't feel comfortable getting ahead of Ford with that information as some people might try to force failure in order to get it replaced.

Additionally, not everyone who had HVBJB failure drove in the same way. I've personally talked to many people with failure who described their driving style, all very different. Also, many, many had failure in the snow, where I would assume, they weren't driving in an aggressive manner.

Therefore, I think the appropriate avenue is to educate people on why this happens and explain how the contactor heats up. With that information people should be able to make informed decisions on how to minimize possible failure. Since there are many ways that failure occurs, some of which are just a stroke of bad luck, I don't want to be the one who says "don't do this and you'll be okay". The evidence doesn't support that it's that simple.

I think it's a wise decision to drive more conservatively until the recall is performed however 99% of owners don't experience HVBJB failure and drive the car as it's to be driven. All being said, I did elaborate a little more on that section.

Is there anything you’ve seen tied to L3 charging…? I notice you keep saying “draw” which interpret as using battery, not pushing power to battery…?

 

[Timelessblur]

All-in-all this is a big bummer. Half the fun of driving this car is the acceleration. Now I'm going to be babying it for the next couple of months while waiting for recall notice, dealership appointment, and parts coming in. I'm a Mach E fan through and through but this really is a damper on the ownership experience. I've had recalls before on other cars but this one really sucks because you can be stranded anywhere without any warning signs.

If I had to have a guess is along as you are not doing drag strip launches over and over again you are fine and even then for most I bet you are fine. This could easily be the contacts are not closing enough or some contaminated is in the contact plates causing a bad connection. From there they start over heating and weld together.
I would not be shocked if we find it is going to be a small subset that have to have the part replaced as it will trace down to batches of parts made from one supplier and even then a subset of those from the supplier.

that being said I am now tempted to sit on getting my windshield and roof recall done to batch it with this one as well along with the 20k mile maintenance.

 

[EELinneman]

When you go to sell the MME one day you can advertise that it "Tows Well"

Our dealership here decided this would be the best way to avoid MME's falling from lifts:

Ladies and Gentlemen, let me introduce our next candidate for the Darwin Award......

 

[DevSecOps]

Is there anything you’ve seen tied to L3 charging…? I notice you keep saying “draw” which interpret as using battery, not pushing power to battery…?

Let me say that I have a GTPE and yesterday I charged at L3 in South lake Tahoe and today I'm driving 8 hours and will hit 3x DCFC. Normal driving and charging should be fine, but nothing is guaranteed.

 

[DevSecOps]

Recall issued:
https://www.cnbc.com/2022/06/14/for...g-mach-es-due-to-potential-safety-defect.html

Where have you been?

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