How to log into the engineering menu Xiaomi Mi 8: secret codes and features

Xiaomi Mi 8 is the flagship smartphone of 2018, which is still popular today due to its powerful hardware and flexible firmware. But even experienced users do not always know that under the hood of MIUI hidden engineering menus — a tool for fine-tuning hardware components, testing modules and troubleshooting. In this article, we will discuss how to safely access hidden settings, what features are available there and what risks should be considered.

It's important to understand that the engineering menu is not just a "secret chip", but a professional tool designed for service centers and developers. Careless actions can lead to a loss of warranty, malfunction of the smartphone or even complete failure of individual modules, so before experiments, we recommend carefully study all warnings and create a backup of data.

Unlike standard MIUI settings, the engineering menu allows:

  • 🔍 Testing the job GPS, Wi-Fi, Bluetooth and other wireless modules with technical data output.
  • 📡 Configure network settings (including options that are not allowed in the normal interface, such as forced switching between the two networks) 2G/3G/4G).
  • 🔋 Calibrate the battery and check the actual state of the battery (including data on charging cycles).
  • 🎤 Diagnose microphone, speakers and vibration output with signal levels output.

What is an Engineering Menu and Why You Need It

The Engineering Menu (or Engineer Mode) is a hidden partition of the Android operating system that provides low-level access to the hardware components of the smartphone. In the Xiaomi Mi 8, it is implemented on the basis of the standard menu from Qualcomm (since the smartphone is equipped with a Snapdragon 845 chipset), but with some modifications from Xiaomi.

The main tasks of the engineering menu:

  • 🛠️ Diagnostics of malfunctions: checking the operability of sensors, cameras, communication modules without the need to disassemble the device.
  • ⚙️ Fine tuning: changing network, sound, display settings that are not available in standard settings.
  • 📊 Technical data collection: log output, signal levels, component temperature for performance analysis.

For example, you can force VoLTE (voice over 4G) on an engineering menu if the carrier supports the technology but it is not activated by default, or check why GPS is unstable by displaying data on the number of satellites and signal level.

⚠️ Note: Changing the settings in the BandMode section can lead to loss of communication. If you are not sure about your actions, it is better to use automatic settings (Auto).

How to enter the engineering menu on Xiaomi Mi 8

There are several methods to open the engineering menu, but not all of them work on the Mi 8 due to the features of the MIUI firmware.

Method 1: Using the USSD code

The easiest way is to enter a special code in the phone application:

  1. Open the standard phone application.
  2. Go to the keyboard tab (as if you are going to dial a number).
  3. Enter the combination: ##4636##
  4. On the screen will appear the Testing menu with the main sections of engineering settings.

This code works on most Xiaomi smartphones, including the Mi 8, but can be blocked on some custom firmware or regional versions of MIUI (for example, for China).

Method 2: Using the MTK Engineer Mode (Mentioned Menu)

If USSD-The code did not work, you can install a third-party application:

  1. Download the MTK Engineer Mode app from Google Play (despite the name, it works on Qualcomm devices as well).
  2. Launch the application and grant Super User rights (if there is root).
  3. In the main menu, select Engineer Mode (MTK) and the extended menu will open.

⚠️ Note: Apps from unverified sources may contain malicious code. Install only official, high-ranking versions from Google Play.

📊 Have you ever used an engineering menu on your smartphone?
Yeah, often.
I tried it once.
No, but I want to try.
No, and no planning.

Method 3: Through ADB (for power users)

If the first two methods fail, you can use ADB (Android Debug Bridge), which requires connecting your smartphone to your computer and enabling USB Debugging.

Instructions:

  1. Activate Developer Mode on Mi 8: Go to Settings → About Phone and click on MIUI Version 7 times.
  2. Return to Settings → Additional → For developers and enable USB debugging.
  3. Connect your smartphone to your PC, open the command line and type in: adb shell am start -n com.android.settings/.EngineerMode

If the team doesn’t work, try an alternative:

adb shell am start -a android.intent.action.MAIN -n com.android.settings/.TestingSettings

Create a backup copy of the data|Charge your smartphone at least 50%|Disable important notifications (calls, SMS)|Explore the section FAQ end-of-article-->

Main sections of the engineering menu and their functions

After you log in, you'll see a menu with a few tabs, and let's look at the most useful ones.

SectionDescriptionWhat can be customized
TelephonyNetwork and communication settingsForced network standard selection (2G/3G/4G), signal testing, VoLTE setting
BatteryBattery informationChecking the charge level, temperature, number of charging cycles
SensorsSensor testingChecking the operation of the gyroscope, accelerometer, proximity and illumination sensor
LocationGPS and geolocationSatellite data output, coordinate accuracy test
Hardware TestingVerification of hardware componentsTesting of camera, microphone, speakers, vibration output

The most popular section is Telephony.

  • 📶 Forced to turn on 4G Only (useful if the smartphone is constantly switching to the 3G).
  • 🔄 Change BandMode settings to optimize internet speed (e.g., disable unnecessary frequencies).
  • 📞 Check for support for VoLTE and ViLTE (video calls by video) 4G).

💡

Before you change your network settings, write down your current settings (you can take a picture of the screen) and this will help you get it back if the connection goes down.

What can be customized in the engineering menu Xiaomi Mi 8

On the Xiaomi Mi 8, a unique Hall sensor calibration function (used for window cases and magnetic accessories) is available through the engineering menu, which is not available in standard MIUI settings and can solve the problem of spontaneously turning on / off the screen when using cases.

Other useful settings:

1. Optimization of network operation

In the Telephony → Network Select section, you can:

  • 🌍 Manually choose the operator (useful in roaming).
  • 📡 Disable automatic network selection if the smartphone constantly “loses” the connection.
  • 🔄 Change the type of network you prefer (e.g. installing a network) LTE Only for maximum internet speed).

Checking and calibration of the battery

The Battery section displays:

  • 🔋 Battery capacity (may differ from the declared due to wear and tear).
  • 🌡️ Battery temperature (critical values - above 45)°C).
  • 🔄 Number of charging cycles (if more than 500 cycles are recommended to replace).

If the smartphone is rapidly discharged, you can check if the charge controller is lying, for example, if the real voltage is below 4.2V at 100% charge, the battery needs to be calibrated or replaced.

3. Sensor testing

The Sensors section is available:

  • 📱 Checking the gyroscope and accelerometer (useful for games and AR-applications).
  • 👁️ Approximation sensor test (if the screen is not locked during the call).
  • 💡 Checking the illumination sensor (automatic brightness adjustment).

If some sensor does not respond, it may indicate a hardware malfunction or a failure in the firmware.

What to do if the engineering menu is not opened?
If none of the methods worked, the reasons may be: 1. Operator-blocking: some firmware for specific regions (e.g. China) restrict access to the engineering menu. 2. Custom firmware: if you use the unofficial version MIUI custom-made ROM (For example, LineageOS, the codes may not work. 3. Update MIUI: In newer versions of the firmware, Xiaomi can remove or hide access to the engineering menu. MIUI (Install the Shortcut Master app from Google Play – it can find hidden menus even without root rights. ADB-commands with superuser rights (unblocked bootloader required).

Risks and Warnings: What Not to Do in the Engineering Menu

The engineering menu is a powerful tool, but doing the wrong thing can have serious consequences.

  • ⚠️ Changing the bandmode settings without understanding the consequences. Wrong settings can make a smartphone a brick without being able to call.
  • ⚠️ Calibrate the battery through informal methods (e.g., resetting statistics without a full charge cycle) This can cause the charge level to be misdisplayed.
  • ⚠️ Include debugging modes (e.g, USB Debugging or Factory Mode, unnecessarily. It creates malware vulnerabilities.

⚠️ Note: If you accidentally changed your network settings and lost communication, try resetting to factory settings via the Telephony section. → Restore Defaults.If that didn't help, you may need to flash the modem module.

It is also worth remembering that:

  • 🔧 Any changes to the engineering menu reset the warranty (if the smartphone is warranty serviced).
  • 🔄 Some settings (such as Fast Dormancy for battery saving) may conflict with firmware and cause crashes.
  • 📱 If after the changes the smartphone began to overheat or discharge quickly, return all parameters to the original state.

How to Get Out of the Engineering Menu and Get Everything Back

If you have made changes and want to return the standard settings, there are a few ways:

Method 1: Resetting of individual parameters

Most sections of the engineering menu have a Restore Defaults or Reset button, such as:

  • In Telephony, click Set Default to reset network settings.
  • In Battery, select Clear Battery Stats (but only after you’re fully charged!).

Method 2: Complete resetting of settings

If the smartphone is unstable, you can make a hard reset (but it will delete all the data!):

  1. Go to Settings → About the phone → Reset settings.
  2. Choose Reset All Settings (not to be confused with Reset to Factory, which deletes files!).
  3. Confirm the action.

Method 3: Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fastboot Fast Fastboot Fast Fastboot Fast Fastboot Fastboot Fast Fastboot Fast Fastboot Fast Fastboot Fast Fast Fastboot Fastboot Fast

If the smartphone stopped turning on or lost the network, you may need to flash it through Fastboot.

  1. Download the official firmware for Xiaomi Mi 8 (codename dipper) from the MIUI Download website.
  2. Connect your smartphone to your PC in Fastboot mode (press Power + Vol− when the device is off).
  3. Use the Mi Flash Tool for firmware.

💡

Before resetting or flashing, always back up your data via Mi Cloud or locally on your PC.

FAQ: Frequent questions about the Xiaomi Mi engineering menu 8

Can I log into the engineering menu without entering the code?
Yes, if you have root-rights firmware installed, you can use apps like QuickShortcutMaker to find the hidden activity of EngineerMode and create a shortcut on the home screen. However, this method requires an unlocked bootloader and may disrupt some features (e.g. Mi Pay or Widevine). L1 viewable HD-content).
Why did the Internet disappear after the change in settings?
Chances are you have disabled the main frequencies your carrier uses. Return settings to Telephony → BandMode and select Auto for all settings. If that doesn't work, check if Airplane Mode is activated (in some versions of MIUI, it turns on automatically when network settings fail).
How to check if my Mi 8 VoLTE supports?
Go to the engineering menu in the Telephony section → IMS Settings. If there are VoLTE Provisioned and ViLTE Provisioned options on the phone, your smartphone supports the technology. To activate it, you may need to: Update the firmware to the latest version. MIUI. Install SIM-card of the operator that supports VoLTE (for example, MTS, Beeline or MegaFon in Russia) Manually enable the option in the network settings (if it is hidden, use the engineering menu).
Can the processor be overclocked through the engineering menu?
No, the standard engineering menu Xiaomi Mi 8 does not have options for overclocking the Snapdragon 845. This requires: unlocked bootloader, Cast core (for example, FrancoKernel or ElementalX) applications for frequency management (for example, Kernel Adiutor). However, overclocking is fraught with overheating and shorten the life of the chipset. On the Mi 8 this is only relevant for enthusiasts, since the performance of the Snapdragon 845 is enough for most tasks and without overclocking.
How to reset the battery charging cycle counter?
The charge cycle meter cannot be reset, it is recorded in the battery controller. If you see incorrect data (for example, 1000 cycles on a new battery), it can mean: Controller malfunction (replacement of the battery is required); firmware failure (try to refashion the smartphone via Fastboot); Use of a non-original battery (Chinese copies often lie with the data); The only way to "reset" the meter is to install a new original battery.