Xiaomi Mi 8 Pro is a flagship device that hides powerful hardware potential, access to which sometimes goes beyond standard user settings. For deep diagnostics, authentication of components or fine calibration of sensors, developers have left a hidden toolkit known as CIT (Customer Integration Test), which can be accessed without obtaining root rights, using special system commands or combinations of actions in the interface.
Users often look for ways to activate hidden functions to check microphones, vibrator or calibrate the screen after replacement. Sign in to the engineering menu on the Mi 8 Pro is through the code set ##6484## or through the About menu. However, it is worthwhile to understand that careless change of critical parameters can lead to unstable operation of the MIUI operating system. Below we will discuss in detail the secure access methods and functionality of the available tests.
It should be noted that the testing interface may vary slightly depending on the firmware version installed on your device. Global versions of MIUI and Chinese builds sometimes have differences in the toolkit available.
Methods of activating hidden testing mode
There are several proven ways to activate the diagnostic interface on the Xiaomi Mi 8 Pro device. The fastest and most reliable method is to use a special diagnostic interface. USSD-The code that's in the system phone, you don't have to install third-party apps or connect your smartphone to your computer.
Open the standard Phone app, which you usually make calls through. Go to the dial tab and type in the following character sequence: ##6484##. In most cases, the menu will open instantly after you enter the last character, you don't need to press the call button. If the screen blinked and a new window with a white or black background and a test list appeared, you reached your goal.
In some cases, especially on re-enhanced devices or versions with modified phone system applications, the code may not work, so you should use an alternative route through system settings, which is longer, but guaranteed to work on stock firmware.
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If the code doesn’t work, try typing it into the Security app in the search box or use the alternative code ##4636## for advanced battery and network information.
To enter through the settings, perform the following actions:
- 📱 Open Settings and scroll down to the "About Phone" item».
- 👆 Find the line "Version" MIUI» And press it fast. 7-10 once in a row until a pop-up notice appears.
- 🔍 Return to the main settings menu and find the “Advanced Settings” item that appears, or immediately «CIT».
- ⚙️ Select the desired section to start testing components.
It's worth noting that these tools don't require the average user to use them frequently, and they're primarily for service centers and engineers when they're getting a device, but for enthusiasts, they're a great way to check the health of a smartphone before you buy it, or after you fall.
Detailed diagnostics of hardware components
Once you log in, you'll see a list of dozens of items, each one of which is responsible for checking a specific Xiaomi Mi 8 Pro node. For example, the TouchPanel test allows you to check the response of the touchscreen across the entire display area by drawing lines in special zones, which is especially true if you notice "dead zones" or chaotic presses.
The Mi 8 Pro uses an ultrasonic fingerprint scanner embedded in the screen, and the engineering menu can run a Fingerprint test to see if the controller can see the finger and read the picture correctly, as does the front camera and the infrared light sensor hidden in the top speaker.
The sound subsystem is also subject to careful analysis, so you can test the main speaker, the speaker, and the microphones separately, and when you run the Speaker test, the device will play the melody, and when you run the Microphone test, it will record your voice and play it back to check the quality of the recording.
It's important to interpret the test results correctly. If the motor is not buzzing when checking for vibration, it doesn't always mean that the battery is dead or there is a silent mode blocking the tactile return at the system level. However, if the test shows FAIL on a fully charged device, it's a signal of a hardware problem.
Sensor work and calibration
One of the most useful features of the hidden menu for Mi 8 Pro owners is the calibration of the sensors. Over time or after changing the display, the proximity sensor may start to work incorrectly: the screen goes out during a conversation or, conversely, does not turn off when you hold the phone to your ear. In the CIT menu, there is a Proximity sensor item that allows you to reset and recalibrate this module.
The calibration process is usually automated. You'll need to close the top of your smartphone with your palm (simulating a hand-to-ear approach) and then open it at the command of the system. After you successfully complete the steps, you'll see the Pass message. If the calibration fails the first time, repeat the procedure, making sure that the sensor doesn't have a protective film or dirt on it.
And you can also check the accelerometer and the gyroscope, and these components are responsible for turning the screen and the pedometer, and in the Accelerometer, you're going to be asked to put your phone on a flat surface and wait for the virtual bubble to align, and this helps to fix the problem when the interface is floating or games are delayed in tilting.
⚠️ Warning: Do not attempt to manually change sensor sensitivity numerical values unless you understand the physical meaning of these parameters.
For those who are engaged in glass reglazing or display replacement, a color and broken pixel test is critical. The menu has modes that pour on-screen colors (red, green, blue, white), which allows you to visually assess the uniformity of the backlight and the absence of artifacts of the AMOLED matrix installed in the Mi 8 Pro.
Verification of communication and network modules
The modern smartphone is a complex electronics complex. In the Xiaomi Mi 8 Pro, powerful modems are responsible for supporting networks, and they can also be tested. The section responsible for communication is often designated as Sim, Network or GPS. Here you can check the signal level, registration in the network and the operation of navigation modules.
The GPS test will show the number of satellites visible and the accuracy of positioning. If the phone can not determine the location in the navigator for a long time, this test will help to determine whether the antenna sees satellites at all.
Checking Wi-Fi and Bluetooth modules allows you to see them MAC-This is useful if you have lost your Bluetooth address in your settings or your phone has stopped seeing the Wi-Fi network, and a successful scan in the engineering menu confirms that the module is physically intact, and the problem is likely software.
| Parameter of the test | Description of function | Normal result |
|---|---|---|
| Version | Information about the CIT version and drivers | Display of the current version |
| TouchPanel | Checking the responsiveness of the touch screen | Lines are drawn without breaks |
| RGB | Color display test | Uniform color without stains |
| Vibrator | Vibrator check | You feel vibration. |
| Receiver | Talk dynamics test | Test sound heard |
If you see persistent errors in the communication tests, it makes sense to reset the network settings or flash the radio module, but in 90% of cases, software failures are solved by simply resetting the settings to the factory through the recovery menu.
Advanced settings and reset parameters
Inside the engineering menu, you can not only diagnose, but you can also reset some parameters, so the Top or Back button allows you to go back to the main menu, and the Fail or Pass button allows you to complete a specific test, but beware: there is no Cancel button for calibration processes that are already running.
There is also the ability to view detailed battery information similar to that output by code ##4636##. Here you can see the actual capacity, the number of charge cycles (if supported by the controller) and the core temperature.
☑️ Checklist before resetting settings
Some users are looking for the ability to unlock a bootloader or change a region, and it's worth dispelling the myths: the CIT engineering menu is not designed to unlock a bootloader. It requires a separate Mi Unlock utility and account binding, and trying to find such features inside a CIT is useless.
⚠️ Warning: Changing settings in sections marked as "Engineering" or "Debug" can lead to loss of warranty and unstable phone performance. Use only testing sections (Test only).
Typical problems and ways to solve them
A common problem is when the phone freezes or flies back to the desktop after entering the test menu, this can be due to a conflict of processes or a lack of RAM if many background applications are running.
Another common question is the lack of sound in the speakers during the test, although they work normally, which may indicate a failure in the switching of audio channels, in which case the device restart helps, and if the problem persists, it may be damaged plume speaker or audio codec itself on the board.
If you have updated the firmware and the menu is gone or stopped opening by code, check if the dial function is disabled. USSD-codes in operator settings or call-blocking applications. Sometimes antiviruses can block execution of system scripts run by code # # #6484##.
What to do if the phone goes into a cyclical reboot after tests?
For Mi 8 Pro owners with a replacement display on the non-original, color and touch screen tests can show errors or incorrect values, since the controllers of the copies of the screens are often different from the factory.
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The engineering menu is a powerful diagnostic tool, but it's not a panacea, it helps to detect a malfunction, but it can't always fix a hardware breakdown on its own.