KeyMaster G3 Bench Mode Issue on SIM2K-251 ECU and TCM Cloning

A user recently reported difficulties cloning a Continental/Siemens SIM2K-251 ECU using the KeyMaster G3 in Bench Mode.
The original ECU and TCM were read successfully, but the donor ECU would not communicate.

After transferring the flash and EEPROM from the original to the donor, the tool reported an error. Once the write was completed, both the ECU and TCM stopped responding on the donor unit.

Several technicians commented that SIM2K-251 cannot be reliably cloned in Bench Mode on OBDSTAR G3. The recommended solution is to switch to Boot Mode, which provides deeper access and avoids security lock issues.
Some also suggested using tools like Flex or MultiProg to perform checksum correction for safer cloning.

This case highlights that while the OBDSTAR X300 Classic G3 is powerful, certain protected ECUs require Boot Mode for stable and successful operations.

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