How to enter Xiaomi settings through dialing: hidden codes

Owning a Xiaomi smartphone gives users access not only to the standard interface, but also to the deep layers of the MIUI or HyperOS operating system. Often, there is a situation when the standard menu is overloaded with unnecessary elements, or access to diagnostic functions hidden from the ordinary eye is required, at which point special character combinations enter through the standard dialing interface come to the rescue.

Using engineering codes allows you to instantly redirect the user to specific configuration sections, bypassing long searches on menu items, this is especially true for technicians and advanced enthusiasts who need to quickly check the battery status, signal quality or hardware version.

In this article, we will discuss the mechanisms of these codes, provide an up-to-date list of commands for different versions of firmware, and explain how to safely use the hidden capabilities of your device, you will learn which partitions are accessible through an asterisk and a grid, and how to avoid blocking important system functions.

The principle of operation of USSD and engineering codes in MIUI

The hidden settings mechanism is based on USSD-querying technologies and internal Android shell commands. When you type in a sequence of characters in a phone book, the system first checks whether it is a standard request to the carrier. If the combination is reserved by the smartphone manufacturer, as in the case of Xiaomi, the request is intercepted by the operating system and redirected to the corresponding system application.

Unlike the usual settings available through the gear icon, the codes allow you to activate the engineering menu or test mode, which is the access level designed to debug the devices before sale, and you can see the actual temperature of the processor, the number of battery charging cycles, or calibrate the touch screen without using third-party software.

⚠️ Note: Introducing some codes may result in resetting certain network settings or changing modem behavior. Make sure you understand the purpose of the command before activating it.

It is important to distinguish between codes that run at the operator network level and those that work locally on the device. Xiaomi teams are in the second category and do not require the presence of a user. SIM-card or account balance to activate most diagnostic functions, which are sewn directly into the firmware device.

💡

Before entering any codes, it is recommended to back up important data via the Mi Cloud cloud service or locally to your computer.

Basic codes for entering the test menu

The most popular and safest way to access advanced diagnostics is to use the universal code ##64663##. This combination instantly opens the CIT (Customer Interface Test) interface, which brings together tools to test each smartphone module, from vibration and display to microphones and light sensors.

Another useful combination of ##4636## takes the user to the phone information menu, and in this section you can go through the app usage statistics in detail, see the current user experience. IP-address and, most importantly, manage the settings of the preferred network type, which often helps with problems switching between the two networks. 4G and 5G.

To check the battery status and discharge statistics, the code ##6485## is used. It displays a table with technical parameters such as residual capacity, battery health and the number of full charge cycles, which are critical when assessing wear before buying a used gadget.

Some codes may not work on global firmware versions, as they are often only available in Chinese builds. However, the basic set of testing features is usually saved in all regions. If the code is not activated, try entering it without pressing the call button - modern Xiaomi shells respond automatically.

Engineering menu and modem settings

One of the most popular features for advanced users is access to the modem's engineering menu. The combination ##3646633### (or variation ##4636## depending on the chipset model) gives access to deep radio settings, where you can force the phone to 2G Only or 3G Only mode, which is useful in areas of uncertain reception, where constant reconnection to LTE puts the battery down.

Band Mode is also available in this section, allowing you to select specific frequencies that your device will be running on, which can greatly improve Internet speed if you are near a tower operating at a specific frequency that the phone defaults on, but changing these settings requires caution.

• 📡 Band Mode: Selection of specific frequency bands LTE and WCDMA.
• 📶 Rf Test: Real-time signal strength and transmitter power check.
• 📍 GPS: Testing of satellite navigation and cold start speed.

⚠️ Warning: Changing the settings in the modem's engineering menu may result in a complete loss of communication.

Note that newer versions of HyperOS may restrict access to some of the engineering menu features or require special permissions, for security and stability reasons, and if standard codes don't open the full menu, your firmware version may have a stripped-down functionality.

Diagnostics of display and touch input

Screen problems are a common reason to call the service, but you can do the initial diagnostics yourself. The CIT menu, called by the code ##64663##, is a touchpad test, and the system will ask you to swipe your finger across all the cells of the grid, coloring them in a certain color, which allows you to identify "dead zones" that do not respond to touch.

There's also a bit of pixel testing and evenness of backlighting, and it's consistently poured in red, green, blue and white, and you can see the matrix defects with the naked eye in a monochromatic background, and it's especially useful when you're getting a new device in a store or when you're buying it from hand.

There is a separate test to test how many touch points a display controller is processing at the same time, and for modern Xiaomi, the normal indicator is support for 10 simultaneous touches.

If the tests show defects, a Hard Reset is unlikely to help, most likely because the digitizer or plume is physically damaged, and the components need to be replaced.

Information about the system and version of the software

Often users need to quickly find out the exact version of the Android build, the security patch number or the firmware compilation date. The standard About Phone menu sometimes hides these details. Using code ##4986## (not working on all models) or going through settings to the Kernel version section gives more technical information.

It's important to distinguish between MIUI and Android, the shell, the base operating system, and the hidden menus, which version of the Bootloader is currently installed, is critical for anyone who's planning to unlock the bootloader to install customized backups.

Also, diagnostic codes can check the bootloader lock status. If the device is locked, installing third-party firmware will not be possible without official unlocking through Xiaomi servers. Status is usually displayed as Locked or Unlocked.

• 📱 Build Number: Unique firmware version identifier.
• 🔒 Bootloader Status: bootloader lock status.
• 📅 Security Patch: Date of the Last Security Update.

⚠️ Warning: Attempting to modify system files without unlocking the bootloader can result in a cyclical device reboot (bootloop).

Resetting settings and emergency commands

There are codes that initiate a complete reset to factory settings, the most famous being ##7780##. It resets with personal files (photos, videos) but deletes all installed applications and their data, returning system settings to the original state, a useful feature for a clean start without losing media content.

The more radical command *2767*3855# (which runs on very old models or specific builds) performs full formatting of internal memory, removing everything irrevocably. On modern Xiaomi smartphones with Android protection, this command is most often blocked or requires confirmation through a Google account.

The use of such codes is justified only if the phone does not boot in normal mode or the settings menu is not available due to system errors. Before using, be sure to remove the SD memory card, if it is installed, so as not to format it accidentally.

💡

Use reset codes only as a last resort when standard input to settings is not possible. Always back up the data beforehand.

Frequent problems and their solution

Users often experience a situation where the code entered does not lead to any result: the phone simply ignores the input or displays the message "Code not found." This may be due to restrictions imposed by the carrier or the firmware version itself. Global versions of MIUI often have a pared-down list of available commands compared to Chinese ones.

Another reason may be the lack of access rights, and some sections of the engineering menu require root rights or ADB (Android Debug Bridge) access, and if you try to change your modem settings without the proper permissions, the system simply won't let you save the changes.

If none of the codes work, the alternative is to use diagnostic apps from Google Play or enter Recovery Mode via a combination of physical buttons, and you can use your computer and ADB utility to send commands directly to the system.