Tools like PuTTY , Tera Term , or NB-IoT/LTE Engineering tools .
If the IMEI change doesn't "stick" after a reboot, the modem is likely pulling the original ID from a protected bootloader partition. In this case, a deep firmware flash is the only solution. Is it Worth It?
Switching USB modes can sometimes cause the device to vanish from the OS. Always keep your original AT+GTUSBMODE value handy to revert the modem to its standard laptop-integrated state.
For many Intel modems, the standard AT+EGMR command used for Qualcomm chips will not work. Instead, engineering commands like AT+XCPERM or specific manufacturer-locked commands are often required.
Often looks like AT+XIMEI="your_new_imei" .
For most users, the Fibocom L850-GL is best used with its default settings. However, if you are a developer working in a lab environment or a hobbyist trying to get a ThinkPad module working on a specific IoT network, the steps above provide the framework for modification.
The ability to see the modem under "Ports (COM & LPT)" in Device Manager.
Correct Fibocom/Intel XMM 7360 drivers installed on a Windows PC.
Most modern L850-GL modules have write-protection on the IMEI sector. If you receive an "ERROR" response to AT commands, your firmware may be locked. You might need to downgrade to an earlier, "unlocked" engineering firmware before the changes will take effect.
Ensure you know your current firmware version, as some methods are patched in newer releases. Step-by-Step Method (Overview) 1. Enabling Engineering/Diagnostic Mode