Manually Replacing ISN in MG1/MD1 ECUs via EEPROM 2025-07-01

Bin · 02.07.2025

Bin submitted a new resource:

Manually Replacing ISN in MG1/MD1 ECUs via EEPROM - A step-by-step tutorial for cloning the ISN to adapt a used MG1/MD1 DME.

A step-by-step tutorial for cloning the ISN to adapt a used MG1/MD1 DME.
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This guide provides a detailed, expert-level walkthrough for manually replacing the Individual Serial Number (ISN) in modern Bosch MG1 and MD1 ECUs by editing the EEPROM dump. This procedure is essential when swapping a vehicle's engine control unit (DME) with a used or donor unit.

Disclaimer: This is a high-risk procedure intended...

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Nate_B · 05.01.2026

Bin said:
Bin submitted a new resource:

Manually Replacing ISN in MG1/MD1 ECUs via EEPROM - A step-by-step tutorial for cloning the ISN to adapt a used MG1/MD1 DME.

Read more about this resource...

When doing this procedure, I have read that the MD1 and MG1 DMEs made after mid 2020 have different security, making them unable to be written. How do you write to these DMEs? And does this process of writing prevent the vehicle from passing smog? The company in Netherlands that unlocks these ECUs for tuning cannot prevent the smog test machines from seeing the modified CVN files, failing the smog test.

Bin · 06.01.2026

Nate_B said:
When doing this procedure, I have read that the MD1 and MG1 DMEs made after mid 2020 have different security, making them unable to be written. How do you write to these DMEs? And does this process of writing prevent the vehicle from passing smog? The company in Netherlands that unlocks these ECUs for tuning cannot prevent the smog test machines from seeing the modified CVN files, failing the smog test.

You’re right — post mid-2020 MG1/MD1 have newer Bosch security, so you generally can’t write them the “old” way. In practice it requires a paid bench unlock service (yes, the expensive ones in EU/NL, etc.), and there’s no public DIY method I can share.
About smog/CVN: if your inspection checks CVN, any tune will change it and it can be detected. Legal pass = stay stock or flash stock back for the test.

Manually Replacing ISN in MG1/MD1 ECUs via EEPROM 2025-07-01

Manually Replacing ISN in MG1/MD1 ECUs via EEPROM 2025-07-01

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