Tesla BMS_a123 "Internal isolation Guide to fix it"

Tesla BMS_a123 "Internal isolation Guide to fix it" Cost, Find Compare and Book best affordable Workshop

1. Introduction

This is generic alert for internal isolation and there could be many reasons for this alert. One of most common reasons could be water ingress inside high voltage battery pack, physical damages on high voltage battery pack etc.

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.

1.1 Why its important to have isolation in electric car?

High Voltage systems are mounted on car chassis. There must be a minimum electrical isolation/resistance in between High Voltage System and Car Chassis to ensure safe car operation.  

There is monitor which is installed in battery, which measure periodically the resistance between the high voltage conductors and chassis.

1.3.1 Internal Isolation

    Internal isolation is related to High Voltage Battery and possible code could be BMS_a123

    • BMS_a123_SW_Internal_Isolation

    1.4 What will happen?

    Low isolation alert will not allow contractors to close until you do not repair High Voltage Battery is replaced/repaired/fixed.

    2. How to Diagnose

    This alert could come because of isolation issue. It need to check additional alerts to find out the exact cause of this alert. 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, you need support for diagnosis. Please contact us.

    2.2 Remote Diagnosis

    Please read more details about Remote Diagnosis in another guide (How to do, 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 do isolation diagnosis in Service Mode

    It could be possible to do self diagnose via Service Mode.

    How to read service alerts in Service Mode

    • On the touchscreen, click Controls > 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.

    Service > Battery > High Voltage

    If everything is good. You will see green circles.

    In case, if there is any High Voltage issue. You will see low resistance value and red circle.

    Tesla BMS_a123 Guide to fix

    Service Mode > High Voltage

    In case, If you need support for diagnosis. Please Connect Us.

    If you need support. 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, support for fixing if possible online support or to organize an appointment with independent affordable workshop.

    Depend on alert/fault code, High Voltage Battery might need to be repaired/replaced.

    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 read more details in another guide. Link

    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?

    3.2 Physical defect of the insulation material

    There could be physical damage on high voltage battery.

    3.3 Contamination

    Contamination (of any size, e.g. dust, bolts, etc.), or water/moisture. One of most common reasons could be water ingress inside high voltage battery pack. Please have a detail look in another guide about Water Ingress/Moisture. Link

    4.4 High Voltage Battery Repair

    In case, if there is any water ingress. High Voltage battery pack need to open and repair. There are some special workshops who can perform such repairs.

    You might need to repair/replace high voltage battery. Please read more details about it in another guide. Link

    4.5 High Voltage Battery Replacement

    In case, if there is any physical damages. You might need to replace high voltage battery pack. Please read more details about it in another guide (Battery replacement cost, how to do etc.). Link

    3. Find and book best Workshop to fix Isolation issue

    If you are looking for Workshop who is expert to fix such issue with best price. Please contact us with details in which country/city, are you looking for.  Contact to Fix Isolation Issue

    4. Alert Code

    Some of most common possible alert code

    • BMS_a123_SW_Internal_Isolation
    • BMS_w123_SW_Internal_Isolation
    • BMS_f123_SW_Internal_Isolation

    BMS_f123

    • BMS_f123_SW_Internal_Isolation
    Tesla BMS_f123 Guide to fix
    BMS_f123_SW_Internal_Isolation Guide to fix
    BMS_w123
    • BMS_w123_SW_Internal_Isolation
    Tesla BMS_w123 Guide to fix

    Please send us "Service Alert" Screenshot via Contact or Whats App +49 (0) 15226242038. We will be happy to help to fix alert.

    4. Online Support/Help

    In case if you need any support or have any question. We will be happy to provide you Online/Remote Support. Please Contact Us.

    5. 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

    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.

    For Repair Workshop Owner

    If you car repair workshop owner and would like to add your workshop in our list. 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.

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    FAQ

    Can i reset the alert?

    It is recommend not do reset alert as long issue is not repaired.

    Is it common issue?

    Yes, it could happen on old battery packs if isolation will degraded due to water ingress. 

    Will cleaning will be the solution?

    It might not help.

    What need to do?

    Need to find out the cause of water leak and need to repair battery.

    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

     

     


     

     

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    Disclaimer: Tesla, Inc. was not involved in the creation of this document. Tesla did not provide us any info. Tesla did not edit, review or authorize us. We gather this information from Tesla official website and other resources.

    Note: It is your responsibility to double check and confirm that the procedures/info mentioned in this blog are applicable to your specific car before performing them. Please contact us or our workshop partner to make sure/confirm. We will be happy to help you.