Electricity from Chinese giant Xiaomi is deservedly considered the benchmark of reliability and availability, but even the most advanced devices sometimes require software intervention. Owners often face situations where standard updates through the application are not enough, and there is an urgent need for deep flashing, this can be due to a locking of the region, malfunctions in the BMS (battery management system), or the desire to install a modified version of the software to improve speed performance.
The process of changing firmware is not just clicking the “update” button in the application, but a complex technical procedure that requires an understanding of the architecture of the device. Controllers installed in the M365, Pro, Pro 2 and newer versions have their own security and operating logic. Wrong actions can lead to the fact that the scooter will turn into a useless piece of metal, so before starting any manipulations you need to clearly understand the risks.
This guide will cover all aspects of your vehicle’s software, diagnostics, board connectivity, and secure data writing algorithms, and how to circumvent regional limitations and restore performance after critical errors that are not fixed by standard means.
Preparation for the flashing procedure
Before you start any action with the program code of the device, you need to provide a safe environment for work. Battery charge should be at least 60-70%, as the process of writing data energy consumption can be unstable, and a sudden power outage is fatal for the controller.
The second critical step is hardware preparation, you'll need a dedicated adapter that connects the scooter ports to your computer, most commonly using a USB-TTL interface or special programmers that are compatible with Xiaomi protocols, without which you can't directly interact with the controller's memory.
☑️ Checklist of preparations
Remember that the software must match the specific model of your device. Trying to pour firmware from Xiaomi M365 on the Pro 2 model will lead to incompatibility of components and failure of the control system. Carefully study the marking on the case and check it against the available firmware files on the network.
⚠️ Warning: Before starting work, be sure to disconnect the scooter from the charging network and turn it off with the power button.
Necessary tools and software
To do this successfully, you'll need a suite of specific software that you don't always find in official app stores. Putty, or similar terminal emulators, is the main tool for serial port management, and allows you to send commands directly to the device's console and receive feedback about the state of the system.
Also part of the process is specialized firmware, such as the Xiaomi Flash Tool (adapted for scooters) or Python-based scripts, which can read.hex or.bin files and correctly write them to the controller’s memory, observing time intervals and handshake protocols.
The following is a table of the major programmes and their assignments that may be required in the process:
| Programme | Appointment | Difficulty |
|---|---|---|
| Putty | Terminal for sending commands | Medium |
| Python + Scripts | Automation of firmware | Tall. |
| WinHex | Editing hex files | Tall. |
| Device Manager | Checking COM ports | Low. |
It is important to install the correct drivers for your USB-TTL converter. Most commonly, CH340 or CP2102 chips are used. If the Device Manager does not see the adapter after you connect, the problem lies in the absence or incorrect operation of the drivers.
💡
Use high-quality wires to connect to pins. Cheap thin cables can cause interference, leading to data transmission errors and firmware failure.
Disassembly and connection to the controller board
Physical access to the insides of the scooter is the first step to success. You'll need to carefully remove the decorative panels that hide the main control board. They're usually attached to screws that can be hidden under rubber plugs. Be careful not to damage the plastic latches of the case.
Once the lid is removed, you'll have access to the controller, and you'll have to find a programming contact group on the board, which is usually four or five pins signed as GND, TX, RX, and 3.3V (or 5V), and that's where you're going to exchange data with your computer, and in some models, those contacts may not be signed, so you'll have to look for a pin in the technical documentation.
The connection must be strictly according to the scheme: GND to GND, TX to RX, RX to TX. Power voltage (VCC) is not usually applied to the scooter through the programmer, as it is powered by its battery. The external voltage applied to the pin of the VCC can burn the computer port or the controller itself.
⚠️ Note: Do not confuse the pins under any circumstances. TX and RX. Cross-connection (TX ce TX, RX ce RX) will not allow to establish communication, and the supply of 12V or 24V to the signal lines is guaranteed to disable the controller.
When the wires are securely fixed (you can use insulation tape or crocodiles for fixing), you can connect the wires. USB-The system must identify the new device and assign it a number. COM-Remember this number, it's going to be used to set up the terminal.
Firmware process via USB-TTL adapter
The most reliable way to restore or update software is to use a serial interface. Once the adapter is connected and the terminal is opened (for example, Putty), you need to set the correct connection parameters. The standard speed (Baud Rate) for most Xiaomi controllers is 115200, but in some cases can occur 57600 or 9600.
To start the writing process, you often need to close certain contacts on the board or press the Reset button when you connect the power, which puts the chip into bootloader mode, allowing you to ignore the main firmware and work directly with the memory. Once you see a stream of characters in the terminal or a command prompt, you can start downloading.
The command to run the firmware process depends on the script you use, and if you're manual, the sequence looks something like this:
load -r -p {memory address} {file name}.bin
go {address memory}The progress bar should move evenly when you're recording, and if you see a lot of error symbols or the process is in place, check the quality of the wires' contact. Communications are the main cause of failure. Don't move the scooter or the wires during the critical recording phase.
What if the process is 99% frozen?
Resetting BMS and eliminating errors
One of the common reasons for flashing is to lock the battery with the BMS system. This happens when the cells are deep discharged or after the cells inside the pack are replaced. In this case, the scooter may turn on but not charge or show battery error. Reset BMS allows the battery to be brought back to life without physical replacement of the cells if they are serviceable.
Resets often require not just reflashing the controller, but changing certain flags in memory or sending a special signal through the diagnostic port. Some wizards use the voltage push method, but software resetting by changing parameters in EEPROM is a safer and more civilized method.
Once reset successfully, you need to do a calibration cycle, fully charge the scooter to 100% and then discharge it before it turns off, which will help the system recalculate the actual capacity and align the cell balance, and if you don't, the percentage of charge readings may be incorrect.
⚠️ Attention: Working with BMS Short circuits in the battery contacts can cause fire. Use an isolated tool and be extremely careful.
If the error returns after a short time after the reset, it indicates a physical malfunction of one or more cells in the battery, in which case the software methods are powerless, and the battery compartment is repaired with the replacement of defective elements.
💡
A BMS program reset is effective only if the physical battery cells (cells) are in good condition and have a residual life.
Unlocking regions and changing characteristics
Many users are eager to reflash the scooter to break the 25 km/h speed limit set for EU markets. Modified firmware allows unlocking the engine's potential, increasing the top speed to 30-35 km/h and changing the recovery algorithms, but this carries risks of overheating and resource decline.
Also popular is the change of region of the device. Chinese versions (CN) may differ from global (GL) algorithms and available functionality in the application. Changing the region requires a complete rewriting of firmware with a change in identifiers.
Remember, changing factory settings can cause the system to run in an unstable way, the security algorithms laid down by engineers will stop functioning normally, and increasing the discharge current can cause the battery to wear out quickly and even bloat in hot weather.
If you're doing this, make sure you back up the original firmware before making changes. It's the only insurance that will allow you to get it back to normal if you fail.