⚠️ DISCLAIMER: Modifying firmware carries risks, including the potential to brick your DME. Always create a backup of your original firmware before making any modifications. Use this tool at your own risk. I am not responsible for any damage.
Supported languages: 🇬🇧 English | 🇺🇦 Українська
Supported platforms: Linux | macOS | Windows
This tool helps you work with VIN & ISN data for BMW MS4X engine control units. It can convert VIN strings to their hexadecimal representation, find/replace VINs in binary DME files, copy ISN between DME files, and apply IMMO bypass patches.
- VIN Replacer (
Alt+1): Replace VIN in MS41, MS42, and MS43 binary DME files
- VIN Converter (
Alt+2): Convert between VIN string and hex bytes
- ISN Copier (
Alt+3): Copy ISN (Immobilizer Sequence Number) between MS42 and MS43 firmware files, with optional IMMO bypass functionality
- About (
Alt+4): Application information and credits
- VIN Editing: MS41, MS42, MS43 DME binary files
- ISN Copying with IMMO Bypass: MS42, MS43 DME binary files
IMMO bypass is supported for:
- MS42 version 0110C6
- MS43 version 430069
Only 512KB (MS42, MS43) or 256KB (MS41) firmware binary files should be used.
VIN + ISN flashing:
- For MS42 and MS43: Requires boot mode activation (see How to Connect)
- Does NOT require checksum correction in MS4X Flasher
- After flashing, VIN + ISN must be synced with EWS using INPA
Connect OBD2 cable, turn ignition to the 2nd position, and open INPA:

Press Shift + F7, then choose "Engine > MS 43.0 for M54"

IMMO bypass flashing:
- Can be flashed without boot mode by MS4X Flasher
- Allows the car to start without matching VIN + EWS ISN
⚠️ CRITICAL: Requires checksum correction in MS4X Flasher after using this feature. Car will not start without proper checksum correction!
This tool has been tested and proven to work on real hardware:
- Platform: BMW E46 with MS43 430069 on M54B30 engine
- Tested combinations:
- VIN + ISN
- VIN + ISN + bypass
- ISN + bypass
Download pre-built binaries for different distributions from the Releases page.
Or run from source:
python3.11 -m pip install -r requirements.txt
python -m mscoderThis project wouldn't exist without:
And it was inspired by E46 Temperature Gauge Hex Generator v1.0
MIT License - see LICENSE file for details.





