Mustang Mach E Says "Stop Safely Now". Why?

I know it's really frustrating to see the Ford Mach E not starting or demanding to stop. If your Mustang Mach E says "Stop Safely Now", it's very likely having an issue with the HVBJB - High Voltage Battery Junction Box. This issue is very common with these models and there has been a recall to fix this for cars of the 2011-2012 model years.

Stop safely now message highlights

• Common reasons:hybrid or electric powertrain problems
• How to fix:dealership only
• Possible consequences:the vehicle may turn off shortly after you see the message
• Priority level:High
• Can you drive?Carefully
• DIY repair:Impossible
• Repair price range:$250-$600

The HVBJB problem in the Mach E explained simply

There is a lot of complex engineering behind modern electric vehicles and I will try not to be very technical in this article. The HVBJB is the junction box that has all the connections that integrate the high-voltage battery (EV battery) to other units in your car.

The first recall was issued promptly after Ford realized the problem was pretty bad. But it was just a software upgrade which did nothing good and people kept reporting the problem on forums.

Very often this happened when the car was charging. Suddenly, the vehicle stopped charging and the owner got the notification on their phone that the charging was interrupted and they needed to unplug and then plug the vehicle again. When they reconnected the charger, the vehicle wouldn't start charging and when attempted to start, the dash said "Stop Safely Now".

The scenarios could have been different, but in most cases, it was exactly during charging. Please note that the "Stop Safely Now" message may also appear in other cases which I will describe later.

Battery contactors overheating - how bad it is?

Well, this is a huge safety issue because potentially it may even lead to fire. Overheated contactors may get stuck closed (basically weld together and never disengage) or stuck open and not come into contact when you attempt to start the vehicle.

Unfortunately, there is no fix for this issue in terms of DIY repairs. You won't even be able to confirm that the problem is with the HVBJB unit. The only thing you should do is call the dealership and report the problem. In some cases, the dealer can even be made to pay for towing your EV to the shop.

The bad news is that almost all modern EVs are highly complicated in terms of their engineering and no DIY inspection and repairs are possible. However, I have some suggestions.

What can you try doing before going to the shop?

Well, if this is the HVBJB problem, I'm afraid there is nothing you can do. Just arrange your visit to the dealership and have your car repaired according to the recall - this will not cost you anything at all. As I understand, the latest recall issued in October 2023 covers the actual problem and comes with part replacement, not just a software update.

But maybe the problem is not in the junction box. In this case, I suggest you should try the following:

• Try turning your vehicle off and then on again - will the Stop Safely Now message disappear?
• Disconnect the 12V battery. This battery powers the control units when your car is off. If you disconnect it for several minutes, the units may reset and you may get rid of the error, at least temporarily.
• Try searching in the infotainment system for other errors. Sometimes, the Stop Safely Now message may show you that there is some problem with brakes, ABS, traction control, etc. You will find additional error messages and warnings, in this case.

Can you still somehow drive with this message?

Well, in most cases, when the Stop Safely Now message is displayed on the dash, your Mustang Mach E will coast to a stop. This means, the car detected the problem with the contactors and turned off the main EV battery. But you will have the steering and brakes as they take power from the 12V battery, so just stop safely.

You won't be able to drive if the problem with the contactors is serious and they were welded together. But sometimes, the vehicle may still drive till the next stop. When you attempt to start it again, it will show you the "Stop Safely Now" message.

Also, the cars that got the first-recall software update will likely keep working but they will lose some power. This is the feature that allows the vehicles to save the contactors from welding by reducing the overall temperature in the system.

Should I go to the recall HVBJB replacement?

As far as I'm concerned, now Ford is replacing the faulty contactors in the high voltage battery junction box with the new type of contactors. They may be heat resistant or just some other problem is solved in their engineering.

So, I strongly recommend you check your Mach E VIN on Ford's website or on the NHTSA website and see if your vehicle is eligible for this recall. If it is, I strongly advise you to go to the nearest dealership and have this part replaced under the recall. Otherwise, you may easily get stranded without any early notice.

If you have some experience with this issue, share it with other Mach E owners - write in the comments below!