How to open the engineering menu on Xiaomi Redmi 8: 3 working ways

The hidden engineering menu on Xiaomi Redmi 8 is a powerful tool for hardware diagnostics, module testing and fine-tuning, designed for service centers and developers, but also available to ordinary users, and can test the display, battery, cameras, speakers, and even modify network settings that are not available in standard settings.

But it's important to understand that not all options on this menu are safe, and some changes can lead to a loss of warranty, malfunctioning of the smartphone, or even a "brickle" so you should weigh the risks and back up the data before experimenting. In this article, we will break down three official ways to log into the engineering menu on Redmi 8, including codes, apps and app. ADB-commands, and also tell you what settings can be changed without harming the device.

What is an Engineering Menu and Why You Need It

The Engineer Mode (or Engineer Mode) is a hidden partition of Android that contains low-level tools for:

• 🔧 Diagnostics of hardware components – check the operability of sensors, cameras, microphones, speakers, etc.
• 📶 Testing of network modules - signal analysis GSM, LTE, Wi-Fi, Bluetooth.
• ⚡ Battery settings - battery calibration, reset charge statistics.
• 🎛️ Changes in system configurations - adjusting brightness, touchscreen sensitivity, processor frequency (in some firmwares).

On the Redmi 8 (model M1908C3JG/M1908C3JH/M1908C3JI), the engineering menu is implemented on the basis of Qualcomm Diag Mode, since the device runs on the Snapdragon 439 chipset. This means that some of the functions may differ from the menu on smartphones with MediaTek processors.

Why would a normal user need to access these settings?

• 🔍 Part authentication – for example, determining the originality of the battery or display after repair.
• 📉 Troubleshooting – if the smartphone has become slower to work, does not catch the network or discharges quickly, the engineering menu will help to identify the cause.
• 🔄 Resetting hidden meters – for example, zeroing the data on the battery charging cycle after it is replaced.

⚠️ Note: Changing the parameters in the BandMode section can lead to loss of communication. On Redmi 8 this is especially true for users who often move between regions with different communication standards (for example, Russia and Europe).

Method 1: Entering through service code (the easiest one)

The fastest and safest method is to use a special USSD-It works on most Xiaomi smartphones, including the Redmi 8, unless the firmware has been heavily modified.

Instructions:

1. Open the phone (calling) application.
2. Enter the code: ##4636###.
3. On the screen will appear the Testing menu with several tabs.

If the code doesn’t work, try alternatives:

• #36446337## is an EngineerMode (MTK) menu call.
• #4636## is a universal code for Android.
• #2846579## – for devices on Huawei/Kirin chipsets (not suitable for Redmi 8, but sometimes mentioned in the instructions).

On Redmi 8, after entering the code, a tab menu will open:

⚠️ Attention: On some firmware MIUI (especially global) code ##4636## can be blocked.

Method 2: Use of Engineer Mode (MTK)

If the service codes don't work, you can install a third-party application. Engineer Mode MTK is suitable for Redmi 8 (despite the name, it works on some devices with Qualcomm chipsets).

Step-by-step:

1. Download the app from Google Play (or APKPure if the Play Market isn’t available).
2. Install it and open it. When it first starts, it will request permission to access the Phone and Memory -- provide them.
3. In the main menu, select MTK Settings (even if you have Qualcomm).
4. If the app doesn’t open the engineering menu, try the Shortcut Master option (look for Play Market).

Advantages of this method:

• 📱 It works on most of the firmware, including custom.
• 🔄 Allows you to save the test log to the file.
• 🛠️ More user-friendly interface compared to the standard menu.

Disadvantages:

• ⚠️ Requires third-party software installation (virus risk if downloaded from non-official sources).
• 🔒 Some features may be limited on blocked downloaders.

Method 3: Activate through ADB (for advanced users)

If the first two methods fail, the Android Debug Bridge (ADB) option remains, which requires connecting the smartphone to the computer and basic command line knowledge.

What you need:

• 🖥️ Computer with Windows/Linux/macOS.
• 🔌 USB-cable (preferably original).
• 📦 Installed Xiaomi drivers and Platform Tools package.
• ⚙️ Included debugging by USB smartphone.

Instructions:

1. Activate Developer Mode on Redmi 8: Go to Settings → About Phone. Press 7 times on MIUI Version. Return to Settings → Additional → Developer. Enable USB Debugging.
2. Connect your smartphone to your PC and confirm the debugging permission.
3. Open the command line (or Terminal) in the folder with the platform-tools.
4. Enter the command: adb shell am start -n com.android.settings/.DevelopmentSettings If it doesn't work, try: adb shell am start -a android.intent.action.MAIN -n com.android.settings/.TestingSettings

If the engineering menu doesn’t open, try the alternative method through Diag Mode:

1. Enter ADB: adb shell setprop sys.usb.config diag,adb
2. Reboot the phone.
3. Try to reopen the engineering menu through a code or app.

⚠️ Note: On some versions MIUI (for example, 12.5+) The setprop sys.usb.config command may not work due to security limitations, in which case only unlocking the bootloader will help.

What settings can be changed without risk

Not all options on the engineering menu are equally useful or safe, but here is a list of sections that can be explored and modified without serious consequences for the Redmi 8:

1. Verification of hardware components

• 📱 Touch Screen Test (useful after replacement of the display).
• 🔊 Audio → Normal Mode – Checking speakers and microphones.
• 📷 Camera – Camera test (front and main).
• 🔋 Battery - battery data (voltage, temperature, charging cycles).

2. Network settings (with caution!)

• 📶 Telephony → BandMode – View supported frequencies (do not change unless necessary!).
• 📡 Telephony → Network Select – manual operator selection (useful in roaming).

System information

• 📊 Version Info – data on the version of firmware, kernel, Baseband.
• 🔍 Hardware Testing – sensor tests (gyroscope, accelerometer, compass).

What you can’t do on the engineering menu:

• ❌ Change the parameters in CDS Information → Radio Information – This can disrupt the communication module.
• ❌ Make changes to Hardware Testing → EMMCCID — memory damage.
• ❌ Activate Factory Reset or Clear eMMC, and it will cause a complete reset.

💡

If you accidentally changed your network settings and your phone stopped catching the connection, try resetting them through Settings. → SIM-maps and mobile networks → Resetting network settings.

Frequent Mistakes and How to Avoid Them

When working with the engineering menu on Redmi 8, users often face the following problems:

1.The code is not working.

• 🔹 Reason: Firmware modified (e.g. customized) ROM).
• 🔹 Solution: Use ADB Shortcut Master to find hidden menus.

2.The menu opens, but some functions are not available

• 🔹 Reason: bootloader blocked or root rights no.
• 🔹 Solution: Unlock the bootloader via Mi Unlock (but it will reset all data!).

3 After the changes, the sound or network disappeared.

• 🔹 Reason: Incorrect settings in Audio or BandMode.
• 🔹 Solution: Reset your network settings in the standard menu or reset via Fastboot: fastboot erase modemst1 fastboot erase modemst2

4.The phone overheats after tests

• 🔹 Reason: Long-term load tests (e.g, CPU Stress Test).
• 🔹 Solution: Let the device cool for 15 to 20 minutes. Avoid repeat tests without interruption.

💡

If you're not sure what you're doing, you'd better take a screenshot of your current settings before you change, and that'll help you get it back in case you make a mistake.

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

If you accidentally changed critical settings, there are several ways to return the smartphone to working condition:

1. Mild discharge

• Just reboot your phone – most of the temporary changes will reset.
• If the menu remains active, close it through the Back button or swipe.

2. Resetting network settings

• Go to Settings. → SIM-maps and mobile networks → Resetting network settings.
• This will return the communication parameters to the factory, but will not affect personal data.

3. Complete reset (if nothing helps)

• Run Wipe Data via Recovery Mode: Turn off your phone. Press Power + Volume up until the Mi logo appears. Select Wipe Data → Wipe All Data.

This will delete all the data, but it will return the factory settings.

4.Recovery via Fastboot

• If the phone doesn't turn on, run it through Mi Flash Tool: fastboot flash all.zip
• Download the firmware for Redmi 8 from the official Xiaomi website.