How to open the engineering menu on Xiaomi Mi 9 Lite: secret codes and functions

Xiaomi Mi 9 Lite

CC9

MIUI

engineering menu

In this article you will find the most relevant ways to enter the engineering menu on Mi. 9 Lite (including bypassing locks on new versions) MIUI 12-14), We will see what functions are available without rights. ROOT, And we'll warn you of the risks of carelessness, and we'll focus on sensor tests, screen calibration, and hidden network settings, all of which are useful in everyday use.

The Engineering Menu (or Engineer Mode) is not a repair shop documentation, but a legal tool built into Xiaomi’s firmware, which the manufacturer leaves for service centers, but is also open to ordinary users, and the key is to know the right commands and understand what each section is responsible for.

Important: on the Mi 9 Lite, the entrance to the engineering menu may vary depending on the version MIUI And regional firmware, like in European assemblies (EEA) Some codes are blocked, and global (Global) or Chinese (China) codes are open-ended. We tested all methods on current firmware in 2026.

How to log into the engineering menu on Xiaomi Mi 9 Lite

There are three main ways to open Engineer Mode on the Mi 9 Lite: through secret codes, the Phone app, or third-party utilities. Let's take a look at each in detail, starting with the most reliable.

Method 1: Code for logging into the engineering menu

The easiest way is to type a special command in the Phone app. Open the dial keyboard and type in:

##4636##

After the last character is dialed, the Testing menu will automatically open, where sections are available:

• 📱 Phone information - data about the model, firmware version, IMEI battery status.
• 📶 Battery information - real charge level, temperature, voltage.
• 📊 Usage statistics – screen time, processor activity.
• 🔧 Wi-Fi settings – Hidden network settings (for power users only!).

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Note: Some Mi 9 Lite firmware (especially: MIUI 12+) This code may not work because of the lock, so try the alternative: ##36446337##, which opens an extended engineering menu with sensor tests.

Method 2: Annex EngineerMode" (MTK Engineer Mode)

If the codes don't work, install the official application from Mediatek (Mi 9 Lite chipset - Snapdragon 710, but some features are compatible). APK from a verified source (e.g. APKPure) and follow the instructions:

1. Install the application by pre-allowing installation from unknown sources in Settings → Annexes → Special rights.
2. Open EngineerMode and select a section MTK Settings.
3. For sensor tests, go to Hardware Testing → Sensor.

Method 3: ADB-Teams (for advanced users)

If the standard methods don’t work, you can use Android Debug Bridge (ADB). This method requires connecting the smartphone to the PC and enabling the developer mode:

1. Activate Debugging on USB In Settings → The phone. → Version. MIUI (Click 7 times on the line with the version).
2. Connect Mi. 9 Lite to your computer and run the command: adb shell am start -n com.android.settings/.TestingSettings
3. If the menu is not open, try the alternative command: adb shell am start. -a android.intent.action.MAIN -n com.miui.engineermode/.EngineerMode

What to do in the engineering menu Xiaomi Mi 9 Lite

The engineering menu provides access to dozens of hidden features, but most of them are for specialists, and we have selected the most useful options that will be useful to the average user without the risk of damaging the system.

1. Sensor testing

In the Hardware Testing section → Sensor can check the work of all sensors of the smartphone:

• 🧲 Magnetometer – reaction to a magnetic field (useful for checking a compass).
• 🔦 Light sensor – automatic adjustment of the brightness of the screen.
• 👆 Accelerometer / gyroscope - a test for tilts and rotation (important for games and AR-applications).
• 📏 Approximate Sensor – Checking to turn off the screen during a call.

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Warning: If the proximity sensor fails, it may cause the screen to permanently shut down spontaneously during a call, requiring cleaning or replacing the sensor at the service center.

Screen calibration

If the Mi 9 Lite touch screen does not respond well to touch or misses presses, calibrate:

1. Go to Hardware Testing → Touch Screen.
2. Press Calibration and follow the instructions (touch the crosses on the screen).
3. After calibration, restart the device.

3. Hidden network settings

In the Telephony section → Network Selecting can be manually selected (2G/3G/4G), Even if it's hidden in the standard settings, it's useful if you have Mi. 9 Lite does not catch the network roaming or constantly switches to the Internet. EDGE.

4. Battery check

Battery Information displays real-world battery status data:

• 🔋 Health – Percentage of wear (e.g. 92% means capacity has decreased by 8%).
• 🌡️ Temperature - temperature in degrees Celsius (normal: 25-40)°C).
• ⚡ Voltage - voltage (optimum: 3.7–4.2V).

Difference Between Engineering Menu and Developer Mode

Many people confuse the engineering menu and the developer option, but these are two different tools:

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Note: Changing the settings in the engineering menu (for example, Band Selection in network settings) can lead to loss of communication with the operator. If after the changes the smartphone stopped catching the network, reset the network settings in Settings → SIM-maps and mobile networks → Resetting settings.

Frequent Mistakes and How to Avoid Them

Even experienced users sometimes make mistakes when working with the engineering menu, and here are the most common problems and solutions:

1. Codes are down.

If you enter #4636##, nothing happens:

• 📱 Check that you are typing code in the standard Phone app, not in Google Phone or other dialer.
• 🔄 Reboot your smartphone and try again.
• 📋 Update the firmware to the latest version MIUI (Sometimes the code lock is removed after the update).

2.The menu opens but is empty

It's typical of firmware. MIUI 12+, where Xiaomi has restricted access to some partitions:

• 🔧 Use it. ADB-teams (described above).
• 📲 Install a third-party app like this MTK Engineering Mode (not working on all devices).

3.After calibrating the screen, the touches were lost

If the sensor is getting worse,

1. Reset the device.
2. Calibrate again, strictly following the instructions.
3. If the problem persists, reset the settings to factory (Settings) → Additionally. → Recovery and discharge).

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Before you change any settings in the engineering menu, take a screenshot of your current settings, which will help you get it back if something goes wrong.

Hidden functions that few people know about

In addition to the standard tests, the Mi 9 Lite engineering menu contains several useful options:

1. Enabling recording of conversations

Some regional firmware has disabled call recording to activate it:

1. Go to Telephony. → Audio → Call Record.
2. Select Enable and select the source of the recording (Mic or Voice Call).
3. Save the settings and restart the phone.

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Note: Recording conversations without the consent of the person you are talking to may violate the laws of your country and use this feature only for legitimate purposes (for example, to store important business information).

2. Increased volume of speaker

If you think the Mi 9 Lite speaker is too quiet:

1. Open Hardware Testing → Audio → LoudSpeaker.
2. In the Max Vol field, increase the value by 5-10 units (usually 150 by default).
3. Check the sound and adjust the value if necessary.

3. Display hidden system logs

In the Log and Debugging section, you can include log logs, which is useful for diagnosing errors, for example, if a smartphone accidentally reboots, logs will help identify the cause.

Security: What not to do on the engineering menu

Some sections of the engineering menu can permanently disable a smartphone if you change the settings at random.

1. Change of settings of the communication module (RF)

In the Telephony section → RF Test can accidentally disable supported frequencies 4G/3G, And then the smartphone stops catching the network. Don't edit the settings if you don't understand the meaning of the settings.

Calibration of the battery without necessity

Battery Calibration is available on the battery menu, but using it without real problems (such as sudden shutdowns at 30% charge) can speed up battery wear.

3. Testing vibration at maximum power

In the Vibrator Test section, you can set the vibration intensity to 100%, but this can lead to damage to the motor during prolonged use.

4. Modification IMEI

In some versions of the engineering menu there is an option to change IMEI. This is illegal and may result in the device being blocked by the operator.

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If you're not sure what the parameter is, don't change it. Most of the options on the engineering menu are for service center professionals.

FAQ: Frequent questions about the Xiaomi Mi engineering menu 9 Lite