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Failure of the high voltage junction box - 2014 Model S


New Member
May 6, 2021
Irvine, CA
About 5 days ago on a short drive in my 2014 Model S (<80k miles) I started getting the error bms_w008 "Vehicle may not restart - service required."

I submitted a service appointment request and the service team actually asked me to come in earlier than my scheduled appointment.

They've now diagnosed the issue and said that the high voltage junction box is failing. "Normal operation of the vehicle is causing the current to jump up which is setting off the alert while driving. In the high voltage system it has to maintain 20 amps right now yours is spiking each time you drive because of road bumps and turns anything moving in the rear seat causes a tapping on this internal switch which is causing the current to spike."

I also recently had to have my 12V battery replaced and they said that they may have been related because the failure of the HV junction box would have left the 12V unsupported."

They've also shared that this is not covered under the warranty because "it is not a component of the HV pack it's just part of the high voltage system". She shared that "the tech did mention that he does see this often in the older Model S so he was pretty familiar with the part failure and was able to duplicate the concern easily."

Now, this is costing $1,607 to repair after paying $~250 for the 12V battery a couple of months ago.

Here are my questions:
1) The fact that is isn't covered under the 8-year battery warranty because it's not a component of the HV pack just a part of the system seems unreasonable to me. It seems like it's critical to the battery and to the drive unit. Am I being taken advantage of here?
2) If this is a relatively common occurrence is this likely to happen again?
3) Is there any other recourse from the failure if this is happening to many other older Model S vehicles? Should it be reported to the State of CA?

Thank you for any help!
  • Informative
Reactions: croman


New Member
Oct 4, 2016
Rocklin, Ca
The high voltage junction box has no part in the creation of 400 volts. Its more like a traffic cop directing and distributing current flow.
Back in say, 2016 Tesla would change it no qustions asked. Now not so much.
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Reactions: Evee
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Feb 23, 2021
Dublin, Ireland
Hi, I’ve just got the diagnosis of my rear HV Battery Junction Box too today.
Mines a 2014 P85+ and about 2 weeks ago got the error saying service required, car may not restart.

Service Centre quoting €2100 to fix here in Ireland and also stating that it’s not part of the HV Battery warranty.
Funny thing is 2 months ago I got the HV Battery replaced under warranty where they also done the 12v and only last month got the eMMC recall carried out!
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Well-Known Member
Mar 10, 2016
The 8 year battery warranty covers the battery itself. That’s it. In fact, that’s why it’s called a “battery warranty”.

The HVJB is not a battery.
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Jul 25, 2013
Squamish, BC
I had mine replaced recently in my 2013 Model S after a series of strange electrical problems (battery heater not working, headlights randomly failing, several "car cannot drive" problems, etc. ). It was not covered under the battery warranty, but was covered by my extended service agreement so I just had to pay the deductible.
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Reactions: kceire
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New Member
Jul 16, 2016
My car just died "0 miles" in my driveway when it was at a out 100 this morning and I didn't drive very much... Now the charge door opens but it won't allow the charge plug to plug in... the white light around the charge port isn't lighting. They said try the cable release of the charge port but I can't find it. I found the orange high voltage connector, but I don't want to monkey around that. Service can't come till Monday. And yes I haven't done the EMMC recall yet (2015 S 85, 80,000 miles)
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