Owners of Xiaomi, Redmi and POCO smartphones often face the need to diagnose a device or gain advanced access to system settings. The standard MIUI or HyperOS interface hides many tools for engineers and service center specialists. These hidden sections allow you to check the health of each module of the phone, from the sensor to the communication modules.
Understanding how to get into the technical menu can be a crucial factor in identifying faults on your own, for example, if the screen reacts to late touches or the speaker makes extraneous sounds, built-in tests will give an accurate answer whether it is a software failure or physical damage.
In this article, we will take a look at all known ways to log into system partitions, look at the codes for dialer code and explain what each option is responsible for. Data security depends on user care when working with these menus, so it is important to follow the instructions clearly.
What is the engineering menu of Android
The Engineering Menu, often referred to as the CIT (Customer Integration Test), is a special diagnostic interface built into the device's firmware. Unlike normal settings, this section is not intended for everyday use by the average user. It provides direct access to the hardware of the smartphone, bypassing standard interface constraints.
The main purpose of this tool is to test the components of the device in the factory, but the menu functionality is also useful in operation, and you can force a GPS test, check the calibration of the accelerometer, or find out the actual wear of the battery that is not displayed in the standard menu.
⚠️ Warning: Changing the settings in the sections marked as "Engineering" or "Debug" can lead to unstable system operation.
There are several levels of access to hidden features. The basic layer includes hardware tests available through special codes. The deeper layer requires activation of developer mode and connection to the computer. MIUI has its own implementation features of these menus, distinguishing it from pure Android.
Basic codes for entry into CIT-test
The easiest and safest way to get into the technical section is to use it. USSD-In the Xiaomi ecosystem, the main code is a combination that launches a full cycle of testing equipment.
Dialer code keyboard: ##6484##. Immediately after entering the last digit (), the phone will automatically go to the CIT menu without requiring you to press the call button. If the code does not work, try the alternative ##4636##*, which opens the phone information menu.
In the list that opens, you'll see a list of all the tests available. Each item corresponds to a specific module. For example, Version will show the firmware version and build date, and Touchpanel will run a dead zone sensor check.
☑️ Checking before testing is started
It is important to understand that some tests may require specific conditions. GSM-modules may need to be removed SIM-The Wi-Fi test uses an on router, and the diagnostics are done either automatically or semi-automatically, requiring the user to perform simple actions on the screen.
Alternative methods through system settings
If you have a carrier or firmware block on your code entry, there is a graphical login method available in the standard Security app, which is pre-installed on all Xiaomi devices, which is especially useful if the phone's keyboard is not properly handling special characters.
To log in, do the following: open the Security app, scroll down to Tools, and select Testing. The system will request confirmation of action, then run the same interface. CIT, what USSD-code.
Another way is to go with the kernel version. → On the phone and press quickly 7-10 This action activates the hidden menu, although its functionality may be limited compared to the full one. CIT-In some versions of HyperOS, this method opens the logging system.
| Entry method | Action. | The result |
|---|---|---|
| USSD Code | Dial ##6484## | The full CIT menu |
| Annex | Safety → Testing | The full CIT menu |
| Information on POs | Settings → About the phone → Version | Assembly information |
| ADB Team | Launching through PC | Extended debugging |
Using embedded applications is preferable for beginners, as the interface is adapted and contains hints. System restrictions in new firmware versions can hide some points, making code via dialer a more reliable option.
Why can't the code work?
Using ADB for Extended Access
For users who need more profound changes than just tests, there is a tool available. ADB (Android Debug Bridge: This method requires connecting your smartphone to your computer via a computer. USB-cable and availability of installed drivers.
The first step is to activate the developer mode. Go to Settings → About Phone and press 7 times on MIUI Version. Then, in the menu "Additional" → "Development by USB" enable "Debugging by USB." Without this step, the computer will not be able to interact with the system.
adb shell am start -n com.miui.cit/com.miui.cit.CITActivityThis command compels CIT activity even if standard codes are locked. To execute the command, open the command line in the ADB folder and enter the code. Successful execution will open the technical menu on the phone screen.
⚠️ Note: When connecting to USB Always select File Transfer Mode and confirm the key print RSA On the screen of the smartphone, otherwise the team will be ignored.
The ADB method also allows you to read system logs in real time, which is useful for finding the causes of sudden reboots. the adb logcat command outputs a stream of system events where an experienced user can find driver errors or application conflicts.
Diagnostics of the main modules of the device
Once in the testing menu, users can access a detailed check of each component, the most useful feature for those who buy a used device or suspect hidden defects after falling or getting moisture.
Consider the key tests worth checking first. Touchpanel lets you draw lines on a screen, identifying insensitive zones. Receiver and Speaker play test sounds to check the cleanliness of the speaker. Vibrator tests the vibration mechanism.
- 📡 GPS: Checks satellite capture and positioning accuracy without using maps.
- 📷 Camera: Takes a test shot and checks focus, as well as the flash.
- 🔋 Battery: Shows current voltage, temperature and charge status in real time.
- 📶 Sensor: Calibrates the proximity, lighting sensor and gyroscope.
Special attention should be paid to the proximity sensor test, and if the screen does not go out when you hold the phone to your ear during a conversation, the problem is often solved by calibrating the menu (PROXENSOR). Press Calibration, close the sensor with your finger and follow the instructions.
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If the screen color test (Red/Green/Blue) shows uneven lighting or spots, it may indicate a degradation of the matrix or problems with the plume.
Frequent problems and their solution
Despite the universality of methods, users often face difficulties, and the most common problem is that the phone simply does not respond to code input, which may be due to the fact that the default settings are a third-party call app that does not support the phone. USSD-Xiaomi.
In this case, you need to temporarily return the standard “Phone” from Xiaomi as the default application, and the code may not work on devices with a modified bootloader or/root-rights if system components responsible for CIT.
Another situation is sticking in the test menu, and if the phone doesn't go back to normal after the tests are done, try pressing the power button for 10 seconds to force a reboot, which is rarely helpful when resetting, but it's only a last resort.
⚠️ Attention: Don't try to change IMEI or MAC-This can lead to the locking of the communication module and loss of warranty.
If none of the methods are helping to get into the menu, it is possible that your version of MIUI has a lock at the firmware level (often found on Chinese versions, cross-stitched to global ones), in which case the only solution is to use ADB or install firmware engineering, which requires high skill.
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The most reliable way to log in is through a native dialer, and if it doesn't work, the problem is probably application conflict or system modification.