The SME module, or System Management Unit, in a BMW is a battery management system (BMS) that controls the high-voltage battery. It monitors the battery’s charging process and health.
If the SME module is faulty, the dealership wants you to replace a new one which takes a long time and is expensive.
There are 3 BMW SME solutions so far!
1. Before resetting, make a backup with “Online ISTA”. Then reset and restore. (By pass ‘tester way’)!
2. If you don’t have an “original SME” then you need an “AOS” tester. Ista online…
3. Manually erase 4 bytes of “crash” data from the “eeprom”. Special note! This doesn’t work every time. It’s located in different places every time!
If the car is 2022 and below, it is “offline”, otherwise all “battery series” are read online.
Here we will show how to repair BMW SME module using CG100X programmer.
This is the SME (System Management Unit) High-Voltage battery cell module.
Remove and disassemble the SME module.
Remove the 4 screws on the top to open shell.
Disassemble the control interface.
Remove these screws.
Lift the cover.
If the vehicle collides, these two blown fuses will short-circuit.
So we MUST replace these two blown fuses before repairing the SME module !!!
This is the BMS module we need to repair.
Disassemble the SME module.
The CPU (Infineon TC275) chip controls the battery data.
We will read and write this module with CG100X.
Run CG100X software, go to BCM function.
Select BMW- SME- I3/I4/IX3-TC175 (read/write).
CG100X will show you the wiring diagram.
Zoom in the diagram and connect module with CG100X via pro v2 adapter.
Then read the Dflash data and save.
Send your data to CG engineer or 3rd party resource to modify data.
Then select the modified data and write back to the module.
Wait until the writing chip is completed.
Then reinstall SME module and install to vehicle.
You will also need to program SME module with ISTA in order to work properly.
Xhorse Multi Prog will also repair BMW SME HV battery cell module in this way. Here is the BMW SME pinout to multiprog.
FYI: Here is another BMW SME solution from UK user.
How to validate after resetting the processed SME:
1.After a car crash, the SME will have the crash data!Example of crash error!
We do it patiently and carefully!
Open E-sys!
Then, enter the “COMFORT MODE” section!
Press the “Start Data Check” button and check that everything is “OK”. If not, “Validate”!
If everything is fine then click the “Read data and create temporal CBB request” button!
Then your “ESYS” will create a “CBB” file in the “Data/CERT” folder.
This is the file for “Validation”. Get the response file based on it!
3.Now reset SME !!! Write virgin eeprom!!!
4.Then, when “SME” checks, it will look like this:
5.Then select and write the validation information you received earlier, as shown in the picture! Then check and everything will be written!
6.NOW SME validated!
7.Go to ESYS and code SME (NCD2.0)!!! After codet go to ISTA! Diag the car!
8.Service function
9.Run service function!
After finish close service function and erase all errors!Now car ready!
What is the logic here?
Validate with original “eeprom”. Save the file! Reset and write the “validated” file!
Please note that this file will be needed if you update in the future. Otherwise, there will be a “Validation” error.
This is a very simple way!
This way, SME can be installed on any car, regardless of model!
This solution also helps solve the SME problem of BMW’s fifth generation high-voltage battery.
Read also:
How to Repair/Program Mercedes W222 Air Conditioning Module by CG100X
How to Repair BMW FRM3 Module with CG100 CG100X Automatically?
