Firmware rollback on Xiaomi M365: official and alternative ways

The Xiaomi M365 is one of the most popular urban scooters, but not always new firmware versions bring improvements. Slowing acceleration, reducing top speed, Bluetooth problems or battery failure are typical reasons why owners decide to return the old version of the software. However, the rollback of firmware on the Xiaomi M365 has nuances: official methods are limited, and informal require caution.

In this article, we will discuss all the working methods of downgrade (including bypassing locks), analyze the risks for warranty and equipment, and give checklists for safe execution of the procedure. Importantly, after a rollback to the version below 1.3.6, the scooter may lose compatibility with the official Mi Home application - this is the only irreversible side effect.

If you're faced with a brick after a failed upgrade, or if you want to get back to the factory settings without losing functionality, you'll find solutions here, but first, let's figure out why Xiaomi is making it harder to roll back and what tools you'll need.

Why Xiaomi is blocking firmware rollback?

The manufacturer limits the possibility of downgrade not out of harm, but for three key reasons:

• 🔒 Security: New firmware often closes vulnerabilities in the controller that could be exploited to crack the scooter (e.g., bypassing speed limits).
• 📉 Compatibility: Updated to version 1.5.4+ Controller stops supporting old communication protocols with the application.
• 🛠️ Hardware changes: in some audits M365 (For example, with the Lingyi engine, new firmware is optimized for modified electronics.

But these limitations are not always justified: For example, version 1.3.6 is considered the most stable version of most scooters released before 2019, but it cannot officially be installed on top of 1.5.8, and that’s where alternative methods come to the rescue.

In 2020, Xiaomi quietly removed the M365 firmware archive from the public domain, but enthusiasts saved it on forums like Xiaomi Today and 4PDA.

Preparing for a rollback: what to do before the start

Before proceeding with the procedure, make sure that all the preliminary steps are followed. Failure to comply with at least one item can lead to a breakdown of the controller!

Charge the battery before 60-80%|Download the archive with firmware (verified version)|Prepare the cable. USB-TTL (alternative methods)|Install drivers CP2102/CH340|Backup current settings in Mi Home-->

Pay special attention to firmware selection. Not all versions are compatible with your scooter revision! To determine the hardware version, look at the sticker under the controller lid (near the controller lid). QR-It's a code:

• 🔧 Controller model (e.g, MINI_BLE_ESC_V3.3)
• 📅 Production date (until 2018 - old revisions, after - new ones)

If your scooter is released after July 2019, a rollback on versions below 1.5.4 may cause an ERROR 21 error (motor incompatibility).

⚠️ Note: If the scooter is warranty, rolling back the firmware in an informal way will lead to its cancellation. Xiaomi official service centers determine the change of software by the controller logs.

Official method: rollback via Mi Home (limited cases)

The only legal method is to use the proprietary Mi Home app, but it only works in two scenarios:

1. If the current firmware is newer than 1.5.8, and the target firmware is 1.5.8 (the latest stable version from Xiaomi).
2. If the scooter was purchased in Europe and the firmware was updated to 1.6.0+ with a speed limit of 20 km / h (in this case, a rollback to 1.5.8 is available without restrictions).

Instructions:

1. Connect the scooter to the Mi Home via Bluetooth.
2. Go to Device Profile → Settings → Firmware Update.
3. If an older version is available, a roll back button (usually gray) will appear.
4. Confirm the action and wait until the completion (about 5-7 minutes).

If there is no rollback button, your current firmware does not support this method, in which case move on to alternative solutions.

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Before rolling back via Mi Home, turn off the Internet on your phone – this will prevent the new firmware from automatically downloading immediately after the downgrade.

Alternative methods: firmware via USB-TTL and ST-Link

If the official method is not available, there are two reliable options: firmware via a USB-TTL adapter (for STM32-based controllers) or ST-Link (for deep recovery), the first method is simpler and suitable for 90% of cases, the second for “brick” scooters.

What you need:

• 🔌 USB-TTL Adapter (recommended on the basis) CP2102 or CH340)
• 🖥️ Programme STM32 Flash Loader (or ScooterHacking Utility) for Windows)

Step-by-step instructions for USB-TTL:

1. Disassemble the scooter and find the firmware connector on the controller (4 pins: GND, TX, RX, 3.3V).
2. Connect the adapter to the connector, observing the polarity: USB-TTL → Controller GND → GND TX → RX RX → TX 3.3V → 3.3V (Not necessarily, if the power comes from the battery)
3. Run STM32 Flash Loader, select a port and download the firmware file.
4. Click Next and wait until it is completed (about 3-5 minutes).

⚠️ Attention: If the scooter does not turn on after firmware, check the correct connection TX/RX. Mixed contacts are the most common reason for bricks".

Solving errors after rolling back firmware

Even if you're successful downgrade, you can have problems, and here are the most common ways to fix them:

• 🚨 Mistake. 10/21: This means that the firmware is not compatible with the hardware revision, 1.3.6_mod.bin new-engine).
• 🔋 The scooter is not charged: reset the settings BMS (Turn off the battery for 5 minutes).
• 📱 Not Connecting to Mi Home: Install an older version of the app (e.g. 5.6.51) or use it M365 DownG.
• 🛴 Twitching during acceleration: controller calibration is required (hold the power button). + gas).

If the scooter becomes unstable after the rollback (for example, arbitrarily brakes), the problem is likely to be incorrect calibration of Hall's sensors.

1. Raise the front wheel.
2. Turn on the scooter and scroll the wheel manually at 3 revolutions.
3. Hold the brake and gas at the same time for 5 seconds - this will reset the calibration.

For complex cases (e.g., ERROR 36 error), firmware may be required through the Open Scooter Tool, an advanced tool for diagnosing and repairing Xiaomi controllers.

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Patched firmware (such as CFW) often solves 21/36 errors, but can cancel warranty and reduce battery life due to altered charge algorithms.

How to keep a guarantee when rolling back firmware

Officially, any unauthorized downgrade is void of warranties, but there are ways to minimize the risks:

• 📄 Save the original firmware: before rolling back, make a dump of the current software through STM32 Flash Loader (file) backup.bin).
• 🔄 Restore the original before visiting the SC: if the scooter requires repair, swipe back the factory version.
• 📋 Delete logs: Some firmware (e.g. 1.5.8) retains update history. Use ScooterHacking Utility to clean logs.

It is important to understand that Xiaomi service centers in Russia and Europe rarely check firmware during warranty repairs (for example, when replacing a battery or wheel), however, if you have problems with a controller or BMS, software verification is mandatory.

If you are not sure about your skills, it is better to contact specialists who provide firmware services with the preservation of warranty stickers (for example, through services like ScooterService or Xiaomi Repair).

FAQ: Frequent questions about the rollback of firmware on Xiaomi M365