Xiaomi Cit Test: What is it and how to check your smartphone

Many Xiaomi, Redmi and POCO smartphone owners will eventually encounter a mysterious menu that appears after entering a special combination of numbers: the so-called CIT test, a built-in tool for engineers to conduct in-depth diagnostics of all components of the device, which, unlike standard tests available to the average user, gives access to hidden hardware check functions, allowing you to detect malfunctions that are not visible in everyday use.

If your phone is starting to behave strangely, the sensor is glitching, the microphone is floundering or the battery is quickly running out, this section can help identify the culprit. The engineering menu is not a toy for entertainment, but a serious tool that requires careful handling, since changing some settings can lead to malfunctioning of the system.

In this article, we will discuss in detail how to get into the testing mode, what the codes mean, and how to independently check the serviceability of each module of your gadget without contacting the service center.

What is CIT Mode and Why is it Needed?

CIT stands for Customer Integration Test, or more broadly, a factory build quality test, and is designed to quickly test the health of all hardware components immediately after assembly on a conveyor or when a device is accepted at a service center.

Unlike the standard About Phone menu, where you only see the dry digits of Android and MIUI, CIT allows you to control each sensor in real time. You can turn on the flash, make the motor vibrate, display clean colors to check the matrix or record sound from each microphone, which is critical for detecting hardware defects that can be software-masked as system errors.

For the average user, access to this menu allows for self-diagnosis before buying a used device or when there are sporadic (periodic) failures. Instead of wondering why Wi-Fi is turned off, you can run a radio module test and see the signal level and packets being transmitted in real time.

⚠️ Warning: Do not change the values in the sections, the purpose of which you do not understand. resetting the sensor or changing the display parameters unnecessarily can lead to incorrect touch screen or color reproduction, requiring flashing.

How to enter the CIT Engineering Menu

There are several proven ways to activate the diagnostic mode on Xiaomi devices, the simplest and most reliable method does not require root rights or a connection to a computer, just a standard “caller”.

Open the Phone app (set number) and enter the combination ##6484##. If the code is entered correctly, the system will automatically redirect you to the test menu. On some models or in certain regions, the combination may differ, such as #4636##, but it often leads to the phone information menu rather than the full CIT.

If the code doesn't work, your firmware may be blocking direct access, so you can use an alternative route through the settings:

• 📱 Go to Settings. → The phone.
• 👆 Find the Kernel version (Kernel version).
• 🔁 Press it. 5-10 quick-touch.
• 📋 In the menu that appears, select Manual Test or CIT.

Once logged in, you'll see a list of all the tests available. Some of them may be labeled "Fail" if the system automatically detects a problem when booting. To start checking a particular module, just click on the corresponding line in the list.

Decoding of basic tests and error codes

The test menu interface may seem overloaded, but it's logically structured, each item being responsible for checking a specific node, and when you run a test, the screen often turns a certain color or displays text information.

The test results are usually displayed as Pass (successful) or Fail (error) status. If the test is passed, the system can automatically move to the next item or require your confirmation, and if you make an error, you will see a red indicator or a beep.

Let’s look at the most important tests for the user:

• 🔴 Red/Green/Blue: Check the display matrix for broken pixels and uniformity of the backlight. Carefully examine the screen for points that do not change color.
• 🔊 Receiver/Speaker: Check the speaker and the main speaker, you should hear a clear sound without wheezing or crackling.
• 🎤 Sub/Mic: A microphone test. Record your speech and listen to it. It helps you detect a quiet sound or noise.
• 📡 GPS/WiFi/BT: Test antennas and communication modules, test to see if the device sees the network and satellites.

Checking the display and touch screen (Touch Panel)

One of the most common reasons for using the service is screen problems. In CIT mode, you can do a detailed diagnosis that is not available in normal mode. The display test usually begins with a cyclical switching of colors: red, green, blue, white and black.

Watch the image closely. You can see the black background with the broken pixels (light spots) and the white background with the spots (clouds) or the yellowness around the edges. Touch Panel, run the test.

In sensor mode, you'll be asked to swipe across all the grid lines or paint over certain areas. Importantly, press firmly, but not fanatically. If the line is interrupted or the sector is not painted over, there's a disruption in contact or physical damage to the digitizer.

Also in this section, a Multi-touch test is often available, which shows how many simultaneous touches your screen supports. For modern Xiaomi, the norm is 10 touch points.

Diagnostics of camera, sound and communication

Camera module in CIT-If you have a smartphone with three or four cameras, the test will suggest switching between them (Wide, Ultra-wide, Tele, Macro).

Please note the following aspects:

• 📸 Focus: Point the camera at the text. The image should be clear, without "floating" the focus.
• 🌫 Dust: Take a picture of a white wall or sky, and the black dots in the photo may indicate dust under the lens, which is a guarantee case.
• 🎥 Video: Check if sound is recorded while shooting video and if stabilization works.

The WiFi Test (Sim Card Test) will show you the IMEI-code, signal level (RSSI) If the phone is not catching the network well, compare the numbers. RSSI with another device at the same point. 0 (for example, -50 dBm) better than -110 dBm.

⚠️ Attention: In the camera test, the flash may be turned on at full power. Do not look directly into the LED from close range, so as not to damage the retina of the eyes.

Battery and sensor test

The power section will show the actual battery capacity, the number of charge cycles (on some models) and the current voltage, which is useful for assessing battery wear.

The sensors are also checked here:

• 📏 Accelerometer/Gyroscope: Check the gyro and the accelerometer, put the phone on a flat surface, the values should be close to zero. Tilt the device - the numbers should change smoothly.
• 💡 Light Sensor: Light sensor. Close the top of the screen with your hand - the brightness should change or the test will show a change in the values of the luxmeter.
• 🧲 Magnetometer: Compass. May require calibration by rotating the phone in the air.

If the battery test shows Fail status, it often means that the power controller cannot read the data from the cell correctly, which can be a sign of bloating or deep discharge.

Frequent problems and their solution

Users often experience a situation where the test does not start or shows an error, although the phone is working normally, this can be due to a software failure or a "glitch" of calibration.

If the touchscreen test fails, try to clean the screen and double-check. If the problem persists, you may need to recalibrate (if this option is available in your version of MIUI) or completely reset (Wipe Data).

In case of Baseband errors, it is often helpful to flash the modem or reset the network settings. However, if the CIT shows Fail to the camera or speaker immediately after turning on, the plume or module itself is likely to physically break.