Xiaomi smartphone owners often hear about the existence of a hidden partition of the system that allows you to access deep hardware settings. The engineering menu is not just a toy for the curious, but a powerful diagnostic tool necessary to test the health of communication modules, display and sensors. Many users are trying to find a way to activate this mode to improve the quality of reception of the signal or learn the real technical characteristics of their device.
But the standard MIUI or HyperOS shell interface hides these features from the eyes of the average consumer. Developers do this for safety, so that inexperienced actions do not lead to software failures. However, knowing the right combinations and utilities, you can legally access diagnostic data. It is important to understand that changing the parameters in this section requires caution and understanding the consequences.
In this article, we will take a look at all the known ways to enter the hidden testing mode on the various models of the Chinese company’s phones. CIT-We'll also discuss which parameters can be changed and which ones are better left unattended so as not to disrupt the stability of the gadget.
What is it? CIT-Menu and why you need it
Under the acronym CIT (Customer Integration Test) is a specialized firmware section designed for factory testing of the device, where engineers in the manufacturing industry check every component of the smartphone before packaging, and for the end user, this tool is useful primarily for deep fault diagnosis when standard methods fail.
This mode isolates the problem, for example, if you have a bad microphone, you can run a microphone test and see a real-time graph of the sound wave, and it gives you a clear idea whether the software is a problem or if the physical hardware component is out of order, and without this tool, diagnostics becomes divination on coffee grounds.
The menu features cover almost every node on a smartphone, from calibrating the accelerometer to checking the color reproduction of the matrix, and is automatically or manually diagnosed, giving a "Pass" (successfully) or "Fail" (error), which is especially true when buying a used device or after a fall, when you need to make sure the integrity of the internal plumes.
⚠️ Warning: Making changes to the radio settings or sensor calibration without professional equipment may cause the phone to malfunction. Use the mode only to view data or run tests.
And it's worth noting that this section is usually minimalist and graphically non-essential, and it's not really a beautiful animation, it's just test lists and technical data, and it's designed specifically for speed and clarity of information for the technician, and understanding this helps you to get things right on the screen and not be intimidated by ascetic design.
The main way of entering through the system code
The simplest and most common method of activating a hidden interface is the use of a special device. USSD-It's built into the firmware at the system level and runs on most models, including Redmi and the Redmi. POCO. It does not require root rights or a computer connection, making the method as accessible as possible to any owner.
To use this method, open the standard Phone app you make calls through, and type in the following character combination:
##6484##Once you enter the last star, the dial will automatically reset and the window will open. CIT-On some versions of the shell. MIUI The code may be different or blocked by the operator, in which case the system will simply ignore the input or issue a message about a connection error, which means that you need to find an alternative path.
☑️ Checking before entering
If the code works, you'll see a list of all the tests available, and you'll be able to navigate here by simply touching it, and you just have to press the back button or the call end button to exit.
Alternative codes for different versions of MIUI
Xiaomi's ecosystem is huge, and the firmware for different regions can have its own peculiarities. Sometimes the core code doesn't work, and then alternative combinations come to the rescue, and they can be relevant for global versions, Chinese firmware or older smartphone models released a few years ago.
Try entering one of the following codes in the dialer if the standard version does not work:
- 🔧 ##3646633## - Classic MediaTek code running on older Redmi models.
- 📡 ##4636## - opens the phone information testing menu (relevant for pure Android and some shells).
- ⚙️ ##64663## - variation of the main code for some modifications of the system.
- 📱 ##8255## - code to run the GTalk service (rarely found in old menus).
Special attention should be paid to the code ##4636##. It is often used to force switching of network modes (LTE/3G/2G) and view battery usage statistics. Although technically it is not a complete engineering menu, for many users these are the most important features. On new Snapdragon processors, this code is also often active.
It is worth considering that on modern smartphones with Qualcomm processors and fresh versions of Android, some old codes can be blocked for security reasons. If neither combination works, this does not mean that the phone broke, but only indicates the security policy of the current version of the software.
Using the Mi Test application for diagnostics
If the codes don't work, you can pre-instal a special application that duplicates the functions of the engineering menu, called Mi Test or simply Testing, and you can find it in the Tools folder on your desktop or by searching your smartphone settings.
Starting this app immediately opens up a list of tests similar to what is available through hidden codes.
- 🎨 Display: check for broken pixels and uniformity of backlight.
- 🔊 Sound: Test of speakers, speaker and microphones.
- 📶 Communication: checking Wi-Fi, Bluetooth modules, GPS and cellular.
- 🎮 Sensors: accelerometer, gyroscope, proximity and illumination sensor.
The advantage of using the application over the codes is that you can save the test report, and after you've gone through all the points, the system can generate a log file that you can use when you go to the service center, which proves that there's a malfunction in the documentation, which makes it easier to guarantee.
⚠️ Warning: Do not attempt vibration or display tests if the phone's battery is less than 15% charged.Intensive use of components may discharge the device during the diagnostic process.
In some regions, the application can be hidden or removed from the build, in which case it can be found in system files or installed through ADB, but this requires skills in debugging over USB. For most users, built-in functionality is enough if it is available.
Advanced settings through the developer menu
To get deeper into the system settings that border on engineering, we use the "Developers" section, although this is not a full-fledged one. CIT-menu, here are hidden important debugging and monitoring parameters, useful to advanced users.
To activate this section, you need to go to Settings → About the phone and quickly press 7 times on the item "Version" MIUI» (Or "OS version"). Once the message "You became a developer" appears, a new section will appear in the settings menu.
The following important functions are available here:
- 🐞 Debugging by USB: Allows you to connect your phone to a PC for deep diagnostics.
- 📊 Process statistics: shows CPU load and memory in real time.
- 📡 Mobile networks: choosing the preferred type of network and roaming.
- 🖥️ Interface: setting animation speed and font size.
ADB's Hidden Teams
Using a developer menu is safer than directly interfering with the engineering menu, as the risk of bricking the device is minimal, but changing the zoom settings or the limit of background processes can affect the autonomy and stability of the interface.
Table of the main tests and their appointment
For ease of navigation through the list of tests in the engineering menu, it is recommended to familiarize yourself with their purpose. Not all items are equally useful for the average user, some are designed exclusively for factory conditions.
| Name of the test | Function | Recommendation |
|---|---|---|
| Receiver | Checking the conversational dynamics | It is useful for a quiet sound in the ear |
| Speaker | Basic dynamics test | Checking wheezing and distortion |
| Microphone | Recording and reproduction | Diagnosing hearing problems |
| Touchpanel | Touchscreen check | Search for screen dead zones |
| Camera | Camera and focus test | Autofocus and stabilization check |
When you take a test, you'll need to be careful about what you're looking at on the screen, like in a touchscreen test, you'll need to swipe your finger around the circuit, and in a camera test, you'll need to sharpen your subject, and the system will tell you how to do the check.
💡
Regular diagnosis through CIT-menu helps to identify problems with the "iron" at an early stage, before the expiration of the warranty period.
If the test shows Fail, try restarting the device and checking again. A single failure can be a software error. A repeated failure indicates a physical failure of the component.
Possible problems and solutions
When trying to access engineering features, users often face difficulties, codes may not work and menus may not open, a common situation, especially on newer models with updated security.
One of the reasons for blocking codes is the operator's customization of firmware or regional restrictions, in which case installing a global firmware version or using third-party launchers helps, although this is not always effective, and access may be limited by user rights.
If nothing works, you can use the Engineering Mode app from Google Play, which emulates the hidden menu login using system APIs, but be careful: only download high-rated apps that are proven so you don't bring viruses into your device.
⚠️ Warning: Third-party applications from unverified sources may request excessive permissions. Always check access rights before installing software for system settings.
Remember, the purpose of the engineering menu is diagnostics, not constant system modification, and if your phone is stable, you should not go through the deep settings of the radio module or calibration.