This is the less invasive method—provided the modem accepts the necessary AT commands. However, as some modules have locked NV (non-volatile memory) areas that require vendor-specific keys.
Proper driver installation on Windows or Linux to allow USB serial interface access.
If the response shows your new 15-digit IMEI, the change was successful.
If you own a laptop with this modem and face carrier rejection, your time is better spent: fibocom l850-gl change imei
: Standard AT commands can read configuration data, but writing to security-sensitive parameters requires elevated permissions (Engineering Mode) or proprietary flash tools. Standard Configuration and Diagnostic Methods
: To send these commands, the modem must be in a mode that exposes a serial port (often /dev/ttyACM0 or /dev/ttyUSB0 in Linux). : Some
Always record your factory IMEI before making changes, as it may not be recoverable once overwritten. Methods for IMEI Modification 1. AT Commands (Via Terminal) This is the less invasive method—provided the modem
If your modem is malfunctioning with an "Invalid IMEI" or failing to connect, sharing the specific error or operating system (Windows, Linux, or RouterOS) can help in troubleshooting the connection without risking illegal or hardware-breaking modifications. xmm7360/xmm7360-usb-modeswitch: Tools for the ... - GitHub
Often, a brand new SIM cannot be activated directly through the Fibocom L850-GL module on a laptop
: You must be able to send commands to the modem's serial port (e.g., /dev/ttyUSB2 or similar). If the response shows your new 15-digit IMEI,
: Unplug the laptop battery or remove the M.2 module from the slot for 60 seconds to clear the volatile cache.
—documenting how such modifications might be performed on the Fibocom L850-GL module. The author and publisher do not condone, encourage, or accept any responsibility for illegal use of this information. Proceed at your own risk. Your warranty will be voided immediately, the modem may be permanently damaged, your mobile account could be terminated, and legal consequences could follow.
Changing the IMEI of a Fibocom L850-GL module offers several benefits: