1. Introduction
This is generic alert and there could be many reasons for this alert. In this free guide, you will get information about how to diagnose the exact cause of this alert, what could be the reasons for this alert, how to fix it, How much it could cost to fix the alert, How to get online support, Find and compare best affordable workshop in your region and book an online appointment to fix alert, Information about spare part number and name. You could also buy new and used spare parts with best price etc.
BMS_w172 is an external isolation warning alert. One of High Voltage components (excluding high voltage battery) has too little resistance between HV Components and chassis ground.
In most of cases, it could be issue with battery coolant heater, Large Drive Unit, A/C Compressor, Fuse etc. however other HV Components could be faulty.
The best way would be to perform isolation testing to find out the exact faulty components.
2. How to Diagnose
This alert could come because one or more system/feature is disabled/faulty. The exact cause of this alert could be diagnosed with the help additional alerts.
2.1 How to check additional alert
It could be possible to find out exact cause via Remote Diagnosis, Service Mode. In case, if you need support to check additional alerts. Please Connect Us
2.2 Remote Diagnosis
The exact cause of the alert could be diagnosed via Remote Diagnosis. Please read more details about Remote Diagnosis in another guide (How it work, Cost etc.) Link If you need support. Please Contact Us Phone/Whats App +49(0)15226242038
2.3 Service Mode
It could be possible to find out the exact cause of the alert with the help of services alerts in Service Mode.
How to check service alerts in Service Mode
- On the touchscreen, click Controls (vehicle icon) > Software
- Touch and hold the large word "MODEL" for 4 seconds and then release.
- Enter "service" as access code.
- After clicking on Service Alerts. You can read service alerts. If there is anything wrong with car. It will show in active alerts.
Please read more details in another guide (How to do enable Service Mode) Link
In case, If you need support for diagnosis. Please feel to Connect Us or Whats App +49 (0) 15226242038
Please send us "Service Alert" Screenshot via Contact or Whats App +49 (0) 15226242038. We will be happy to help you to explain alert and how could be fixed, cost, online support to fix alert, organize an appointment with best independent affordable workshop.
Depend on alert/fault code, car might need to be repaired/serviced.
3. How to Fix it
Some of alert could come because of software bugs. Some of alert could resolve after restarting the system, software update/reinstall. To fix some of alerts, car might need hardware repair.
3.1 Restart System
Some of alert could resolve after restarting the touchscreen or power of the car.
Restart Touchscreen
Firstly, you could try with soft reset (restart touchscreen)
How to restart soft reset (restart touchscreen)
- Please shift car into park.
- Hold down both scroll buttons on the steering wheel until the touchscreen turns black.
- Please wait approximately 30 seconds for the touchscreen to restart.
Please read more details in another guide (how to do). Link
Powering Off the Car
If soft reset (restart touchscreen) have not resolved the alert/issue. You could try hard reset (Powering Off the car).
- Please shift car into park
- On the touchscreen please touch Controls > Safety > Power Off
- Please wait for at least for two minutes without interacting with the car. Please do not open the doors, touch the brake pedal, touch the touchscreen etc.
- After 2 minutes, please press the brake pedal or open the door to wake the car (Source Tesla)
3.2 Software issue
Some of alert could be related to software issue.
Software Bug and Glitches
One of reason could be problem with software bug and glitches. Did you get this alert after updating recent software version? If yes, it could be related with software bug and could resolve with future software update. Please send us Service Alert screenshot. So we will inform you if it could be related to software bug. Link
Firmware not updated
One of main reasons could be that firmware is not updated. Have you checked recent update and updated to recent version? If not, we recommend you to do that. Please make sure that the car latest software version. Please read more details in another guide. Link
3.3 Hardware Issue
There could be some hardware issue/faulty. Some of common hardware issues could be followings:
Recent Repair/Service
Did this alert pop up after recent repair/service? If yes, please let us know which repair/service was done recently. Some alerts could pop up if repair/service is not done in proper way. If system/alert has not be reset. Did you use aftermarket/used part?
External Isolation
In most cases, it could be issue with External isolation. Please read all details about external isolation in another guide (How to diagnose, cost, workshop who can perform such tasks etc) Link
Coolant Heater
One of reason could be that coolant heater. Please check more details about possible alert code, how to check, how to repair etc in another guide. Link
AC Compressor
Please check out more details about about A/C Compressor repair. Link
Fuse
One of reason could be that fuse is blow up.
Drive Unit
In case if you have Model S/X with Large Drive Unit. It could be issue with coolant leakage.
Cost
Cost could vary depend on issue, type of workshop, location. If you are looking for online support or affordable independent workshop. Please free to contact us or have a look in Price List
Online Support
In case, if you have any question or need any support/help. Please feel to contact us Contact Us or Whats App +49 (0) 15226242038
Find, compare and Book workshop to Fix it
If are you looking for best workshop who is expert to fix such issue with good price. Please contact us we will be happy to organize an appointment with workshop or find, compare and book best workshop in Workshop Locator
Book an Appointment
If you would like to book an appointment.
Book an Appointment to Fix an affordable Workshop
Buy New/Used Spare Parts
If you would like to buy spare parts. Please have a look in our catalog or Contact Us Phone/Whats App +49(0)15226242038
Alert Code
Possible alert code
1. BMS_w172
BMS_w172_SW_Drive_Iso_Warning
"The battery management system (BMS) has detected low isolation conditions during multiple drive cycles".
2. BMS_u008 and BMS_w172 together alert
In case if you have Model S/X and got BMS_w172 together with BMS_u008. In most cases, it could be issue with Coolant Heater, Compressor, Fuse
Please send us "Service Alert" Screenshot via Contact or Whats App +49 (0) 15226242038. We will be happy to help to fix alert.
Donation/Support
If you feel you have benefited from this guide. Please consider donation, which will help us to create more such free guide for you. It will also show us that this guide was helpful for you. Click on "Donation"
For Repair Workshop Owner
If you car repair workshop owner and would like to add your workshop in our list. Please contact us.
For Car Mechanic
There are some car owner who like to buy spare parts from OEM or Aftermarket and prefer to do Mobile Service, DIY or need support. If you would like to offer this services to car owner in your region. Please contact us.
Comment
Please leave us comment if you have any questions, if you would like to add/edit/delete some content in guide, if you would like to have guide on any another topic etc.
Share this guide Link
Please feel to share this guide/website link.
Frequently Asked Questions (FAQs)
Can I do at Local Workshop, Independent Tesla Workshop?
Yes, you can. However, please make sure that workshop knows how to work to Tesla Cars. If local workshop need any support. Please feel to contact us. We will be happy to provide online shop. You can also find workshop in our Workshop Locator.
Can I do it/repair yourself/myself (DIY)?
Some of repair could be done at DIY. In case, if you needed Tools, Know-How, Time etc. Please feel to contact us. We will be happy to provide you online support.
Note: Please do not work with high voltage components. If you do not need needed/proper Tools, Know-How etc. It could be dangerous.
Mobile repair service?
In some of cases, we could also provide mobile services. Please feel to contact us where are you located and what kind of repair are you looking for.
Car not under warranty, salvage, accident, flood, modified cars?
It is highly recommended to perform repair with independent workshop to save money.
Car under warranty?
In case if your car is under warranty. It is recommended to perform certain repair works (HV Components, ADAS etc) with OEM during warranty period. Wear and Tear Part Repair could be done with independent workshop to save money. Please read more details in another guide. Link
Alert still appearing after repair?
There could be many reasons. Some of reasons could be please make sure that repair was done in correct way, did you restart system after performing repair? did you Reinstall Firmware? Still appearing alert: Please free to Contact Us. We will be happy to provide you online support. Phone/Whats App +49(0)15226242038
