Xiaomi Redmi Engineering Menu: Full Access to Hidden Features

Xiaomi and Redmi are sophisticated computing devices that provide powerful tools for professionals to use behind the familiar MIUI or HyperOS interface. Access to what’s called an engineering menu allows users and service center wizards to conduct deep diagnostics of hardware components, calibrate sensors, and customize the radio module parameters without the need to install third-party applications. This hidden area of the Android interface is created by developers to test the device during the build phase, but it is open to anyone who knows the right commands.

Many users mistakenly believe that logging into this section requires root rights or unlocking the bootloader, which is a misconception. Standard Engineering Mode is built into the firmware by default and activated through system dialing or special ones. ADB-Understanding the working principles of this menu allows you to independently eliminate common problems such as "jumping" GPS, quiet sound in headphones or incorrect touch screen, saving time on a trip to the service.

In this guide, we will detail safe methods for entering hidden parts of the system, consider the purpose of the main tabs and provide specific instructions for calibrating equipment. It is important to understand that changing certain parameters can lead to unstable operation of the device, so every action should be conscious. We will focus on proven methods relevant to the current models of the Redmi Note and Xiaomi series.

What is an Engineering Menu and Why You Need It

The Engineering Menu, often referred to as the CIT (Customer Integration Test) or Engineering Mode, is a low-level diagnostic interface built directly into the Android operating system. Unlike the usual settings that control software functions, this section allows you to interact with hardware directly. Here you can check the health of each sensor, display, communication module and speaker, making this tool indispensable when accepting a new smartphone or finding faults.

The main purpose of this mode is to ensure quality control in the factory and simplify the repair procedure in authorized centers, but advanced users use it for fine-tuning. 3G on 4G/LTE, If the signal is not stable, or calibrate the proximity sensor, which stopped responding to the hand during the conversation. USSD-codes.

⚠️ Warning: Changing the settings in the sections marked as "Telephony" or "Connectivity" may result in loss of network signal or inability to make calls.

It is worth noting that the interface of the engineering menu can vary significantly depending on the version of the MIUI shell and the processor model (Snapdragon, MediaTek, Helio). On devices with MediaTek chips, the functionality is often wider and includes additional tabs for tuning audio and Bluetooth, while on Snapdragon the interface can be more concise. Regardless of the platform, the basic testing functions remain similar.

The main ways of entering through dialing number

The easiest and fastest way to activate a hidden menu is to use the standard Phone app, which doesn't require an internet connection or special access rights, but simply type in a sequence of characters similar to dialing, and then the system automatically redirects it to the desired partition, which works on most Redmi and Xiaomi models.

The most versatile code for Xiaomi devices is the combination ##6484##. When you enter the latest characters, the screen will instantly change and you will see a list of CIT tests. If this code does not work, which sometimes happens on global versions of firmware or depending on the region, you can try an alternative option: ##4636##. The second code opens the test menu of information about the phone, which is part of standard Android, but also provides access to important statistics.

It is important to type the code carefully, without pause. If nothing happens after entering the last digit, it is possible that the carrier blocks the processing of such requests or the firmware of your region has restrictions, in which case use flight mode or check for system updates. It is also important to remember that some new versions MIUI The code entry can be hidden and then the use of the code will be required. ADB-team.

Using ADB to activate hidden functions

In cases where standard codes don't work or the Phone interface doesn't allow you to enter characters, USB debugging comes to the rescue. ADB (Android Debug Bridge) is more professional and requires connecting the smartphone to a computer. It allows you to run hidden system activities directly, bypassing the dialing interface. This is especially true for new models, where manufacturers gradually hide direct access codes.

First, you need to activate the developer mode. Go to Settings. → About the phone and quickly press 7 times on the item "Version" MIUI". Once you have a notification that you have become a developer, go back to the main settings menu, find the "Additional" section and select "Developer" section. USB".

After connecting the device to the PC and installing drivers, execute the command in the terminal:

adb shell am start -n com.android.settings/.TestingSettings

Alternatively, the test menu is:

adb shell am start -n com.miui.calibration/.tests.TestsActivity

These commands will force the corresponding engineering menu activity to run. If the first command doesn't work, try the second one, as the paths to system applications may vary depending on the version of Android.

Detailed calibration of sensors and screen

One of the most useful features of the engineering menu is that you can calibrate the sensors, and over time, the proximity sensor can get dirty or confused, so that the screen doesn't go out during a conversation. On the CIT menu, select "Proximity sensor." Put the phone on a flat surface, close the top with your palm and press "Calibrate." Successful calibration will be confirmed by a green indicator or vibration.

Equally important is the calibration of the accelerometer and gyroscope, especially if you use navigators or play games with tilt control. Select "Accelerometer", put your phone on a perfectly flat horizontal surface and press "Start". The device will determine the position and record the reference values. Similarly, the touchscreen is calibrated in the "Touchpanel" section, where you need to swipe your finger across all the grid cells to check the responsiveness of each section.

For owners. OLED-In the "Display" or "Screen" section, you can start a cyclic change of colors (red, green, blue, white, black) and carefully examine the matrix at maximum brightness. The presence of spots or uneven glow may indicate a defect that is better detected during the warranty period.

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Calibration of sensors is a safe procedure that is recommended after replacing the protective glass or screen, as well as when buying a used device.

Configuring the radio module and improving the signal

The telephony section is often of interest to users who are experiencing problems with mobile Internet. In the menu ##4636## ("Phone Information"), you can find the item "Configure preferred network type" and you can choose between LTE only, WCDMA only or mixed modes.

Using LTE only mode can help in areas with unstable coverage, where the phone constantly jumps between 3G and 4G, breaking the connection. Forced 4G selection stabilizes the signal, but keep in mind: in this mode, incoming calls may not pass unless VoLTE technology is enabled. To return to normal mode, select "LTE/TD-SCDMA/WCDMA/GSM" (set depends on region).

Also in this section you can see detailed statistics of network usage, battery life in different modes and signal strength in dBm. value -90 dBm and above is considered an excellent signal, while values below -110 dBm indicate an area of uncertain reception.

Diagnostics of multimedia and peripherals

The engineering menu allows you to check the performance of cameras, microphones and speakers without installing third-party applications. In the Camera section, you can run a test of the front and rear cameras, checking the focus and presence of artifacts. The microphone test will record your voice and immediately reproduce it, which helps to detect wheezing or quiet sound.

And the vibration test is really worth a special attention, and you can set the duration and the strength of the vibration at the Vibrator, and it's useful if you think the motor is getting weaker or it's humming too loud. RGB-notifications, if provided by the design.

⚠️ Note: When testing cameras, do not point the lens at bright sun or powerful light sources, especially in macro shooting mode to avoid damage to the matrix.

Checking audio output through a 3.5mm connector (if any) or via USB-C is also available in advanced tests. You can choose to output audio to the speaker, headphones or Bluetooth headset to make sure that the corresponding circuits are working, which helps determine whether the problem is software or is in the physical connector.

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Periodically (every 3-6 months) run a full CIT test before upgrading your firmware, which will create a basic hardware status report, and if something stops working after the update, you will know that the problem is the software, not the physical wear and tear.

Frequently Asked Questions (FAQ)