Welcome to the Facebook Tesla BMS_u029/BMS_u018 Group (Group)
FAQ
Compiled from research on the
internet,
Tesla Motors Club and the
FB Tesla BMS_u029/18 Group
Original Author:Ray Johnson Taken
Over/Continued by Chris (KmanAuto)
islandbayy@yahoo.com
(last edited 19 Mar 2024)
What is BMS? BMS stands for Battery
Management System.
Tesla Model S Battery System
and
Battery Management System (BMS) for Electric Vehicles
What is BMS_u029/18 (029/18)? 029/18 is a
non-specific Tesla alert that is usually accompanied by “Maximum battery charge
level reduced. OK to drive. Schedule service”. In most cases your range is
limited to around 60 miles. Or worse, you may completely be unable to drive.
What triggers 029/18? Based on
Group feedback - just happened one
morning, after OTA update, after Factory Reset, after MCU2 upgrade, after
Supercharging or bad luck.
Which Teslas are affected? Currently
primarily limited to 2012-2015 Model S/X’s.
We are yet to hear of any 2016's being affected as they come off warranty and
owners are having to pay for repairs. Neither mileage nor types of
charging habits seem to be immune.
What exactly do the alerts mean?
BMS_u029 = pathological reduction in brick capacity, BMS_u018 = state of
charge imbalance
What's it all mean?and
Tale of Two Errors and
Video - Tesla Error codes and what they mean BMS-U029, BMS-U018, BMS-W164
and
BMS_u029 - What Exactly Is Going On?
What’s wrong with my High Voltage battery pack?
The 029/18 alert is there for a reason. Only further diagnosis by
Tesla or a 3rd party vendor will determine the exact issue(s) with your battery
pack. For example battery imbalance, reduction in brick capacity, hardware
failure, water ingress, etc. Here’s DIY diagnostics
Matt's DIY Diagnostics Also
Recell Diagnostics is offered at no cost. In some cases apps like
Scan My Tesla will help but one needs to know how to interpret the readings.
ScanMyTesla & TM-SPY
What are my options if I’m in need of a
replacement pack and I’m out of warranty? Your repair decision will likely
depend on both personal finances and what you want to do with the car in the
long run. When selecting options, buyer beware and get testimonials. There are
pros and cons to each option listed below. After determining the root
cause(s) of the 029/18 alert, the following are some options.
New or remanufactured replacement pack
from a Tesla Service Center - new $21k ish USD, reman $16k ish. Both come
with a 4 yr/50k mile warranty. New gives you the original 265-270 mile EPA
rated range on an 85 kWh pack. Reman gives you around 240 miles rated range.
Remanufactured replacement pack from a 3rd
party - $10k for 240 mile rated range, warranty about $1250/year extra.
Replacement pack from auto parts salvage
yard - $10k for 240 mile rated range. In some cases, salvage yard may
recommend installers. DIY swap project here
DIY salvage yard replacement pack and
More DIY
Repair of your existing pack at the cell,
brick or module level by a 3rd party - $7k-$10k. Extra warranty cost either
not offered or about $1250/year extra.
Sell your car at a loss with 029/18 alert
known to buyer - currently $7K-$10K.
If you’re comfortable around high voltage
and have the tools/time/know how, remove the pack and attempt to fix
yourself. Cost is your time, learning curve tolerance, and any material
costs. And depends on what needs repair. CAUTION - these packs are lethal if
not managed safely.
Live with the limited range - some
conjecture that living with limited range is temporary
Limited Range
029 Reset device discussion and
More BMS reset device discussion and
Video - reset device owner review
Firmware roll back discussion
Are there any recommended repair shops ?
When selecting either Tesla or 3rd party vendors, buyers beware and get
testimonials. Select your continent from the navigation bar on left to see
Vendors & Professionals in that area.
Warranty terms and conditions after you’ve
resolved your issue. As part of your repair solution decision process,
educate yourself with any warranty terms and conditions. For example time
covered, do you have to return the car back to the original vendor, are any
future BMS_u029/018 occurrences triggered by firmware updates covered, etc?
Do I have any legal recourse if I’ve gotten
the BMS_u029 alert? Currently a class action lawsuit has been filed.
Tesla Model S & Model X Software Update Battery Drain
Where can I find out more?
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