Getting into the hidden section of the system on a smartphone running operating system version 9.0 (Pie) is a non-trivial task, but can be solved with certain knowledge. Engineering menu is a powerful diagnostic tool, hidden from the eyes of the average user, which allows you to conduct in-depth equipment tests, calibrate sensors and even reflash modem However, access to it is deliberately limited by developers for the sake of device security.
On modern devices with Android 9, especially from Chinese vendors, there is no single universal button or command. Google is actively tightening its security policies, blocking standard USSD codes that worked on older versions of the system. Therefore, to log in, special launcher applications or specific sequences of actions in the settings are often required. It is important to understand that incorrectly changing the parameters in this section can lead to loss of signal or inoperability of the touchscreen. Engineering Mode Often special launcher applications or specific sequences of actions in the settings are required. It is important to understand that incorrectly changing the parameters in this section can lead to loss of signal or inoperability of the touchscreen.
In this article we will analyze in detail legal and safe methods of accessing system settings based on Android Pie. You will learn which codes work for different manufacturers, how to use third-party software to emulate input, and which parameters can be safely changed to improve the quality of communication or GPS performance without the risk of turning your phone into a “brick.”
What is the engineering menu and why do you need it
Engineering mode is a special software interface designed for service engineers and developers. It provides access to low-level functions of the smartphone hardware that are not available through the standard settings menu. Using this tool, you can conduct tests microphone, check operation vibration motor, diagnose the battery condition and evaluate the quality of cellular network reception in real time.
The main function of this section is calibration and diagnostics. For example, if your GPS location is inaccurate, this is where you can reset the AGPS data and force a satellite almanac update. Audio profile settings are also available here, allowing you to increase the volume of the speaker or improve the sensitivity of the microphone when recording video.
⚠️ Attention: Changing the parameters in the sections related to the radio module (Radio Information) can lead to the complete disappearance of the network. If you do not know the exact value of the parameter, it is better not to touch it.
Users often seek access to this menu to solve specific problems: a weak Wi-Fi signal, low sound in headphones, or fast battery drain. While some optimizations are indeed possible, it's worth remembering that modern Android 9 algorithms are already smart enough to adjust automatically. Interfering with the operation of the system unnecessarily can disrupt the stability of the operating system.
Before making any changes to the engineering menu, be sure to write down or photograph the original parameter values. This is the only guarantee that you will be able to return everything as it was in the event of a failure.
Universal codes for entering Android 9
The easiest way to get into the hidden section is to use USSD commands. However, on Android 9 this method does not work on all devices. Manufacturers often change these codes or completely disable their processing in the standard Phone application. However, it is worth trying basic combinations that may work on stock firmware or devices with a minimal shell.
Enter the following sequence in the calling application: ##4636##. This is the most common code that opens the Testing menu, where phone information, usage statistics, and Wi-Fi information are available. If after entering the last asterisk the menu did not open automatically, it means that the manufacturer has blocked this access method at the firmware level.
For devices based on MediaTek (MTK) processors, which are often found in the budget segment, other combinations may work. Try entering ##3646633## or #15963#. These codes open a full-fledged engineering menu MTK Engineer Mode, where the Hardware Testing, Location and Connectivity tabs are available.
- 📱 Code 4636: Works on stock Android, Pixel, Motorola and some Xiaomi.
- 🛠️ Code 3646633: Specific for MediaTek chips, opens advanced settings.
- 📶 Code 15963: Alternative input for older MTK devices, may require superuser rights.
- 🔍 Code 0606: Used to check the hardware version and diagnose the display on some models.
If none of the codes work, do not despair. There are many alternative methods, including installing special applications from Google Play that emulate calling these commands or provide direct access to hidden system activities through Intent filters.
Login specifics for popular brands
Each major smartphone manufacturer makes its own changes to the Android shell, which directly affects the ways to access system utilities. On Android 9, the situation is aggravated by the fact that many brands (Samsung, Huawei, Xiaomi) began to hide these menus deeper to prevent accidental damage to the device by inexperienced users.
On devices Samsung with the One UI or Experience UI shell, standard codes are often blocked. Instead, the combination #0#is used, which opens the service test menu (Service Mode). Here you can check the display colors, sensor operation and vibration response, but in-depth modem settings are not available here. To access the full engineering menu on Samsung, you often need to connect to a PC and use specialized software like SamKey or an engineering cable.
Smartphones Xiaomi on MIUI (based on Android 9) have their own unique menu. Try the code ##6484## or ##4636##. The first opens CIT (Customer Inspection Test), where you can test all hardware components. The second leads to the standard debug menu. If the codes do not work, you can try going through the settings: Settings → About phone → Kernel version (pressing multiple times sometimes activates hidden functions, although this is less common on Android 9).
Devices Huawei and Honor with EMUI 9 also have limitations. The code ##2846579## opens the project menu, where network settings and reset settings are available. However, accessing the MTK engineering menu on these devices often requires obtaining root access, which voids the warranty.
| Brand | Main code | Access type | Restrictions |
|---|---|---|---|
| Samsung | #0# |
Service test | No modem settings |
| Xiaomi | ##6484## |
CIT Menu | Only hardware tests |
| Huawei | ##2846579## |
Project Menu | Caution required |
| Meizu | ##3646633## |
MTK Engineer | Full access to MTK |
⚠️ Attention: On Huawei and Honor smartphones after 2019, access to engineering menu codes was completely closed at the bootloader level for most users.
It is important to consider that even if the code is entered correctly, the system may request a special password. Such passwords are often individual for each model or batch of devices and are calculated using IMEI. There are calculators on the Internet for generating such passwords, but their use carries certain risks.
Where can I find a password if the system requests it?
Passwords for entering the engineering menu are often generated based on the IMEI of the device. There are online services and apps (for example, MTK Engineering Mode Password Calculator) that can help calculate the code. However, use them at your own peril and risk, since entering the password incorrectly several times can temporarily block access to phone functions.
Using third-party applications for access
If the built-in codes do not work, the most effective solution on Android 9 is to install specialized applications from the Google Play store. These utilities use system Intent requests to force the opening of hidden engineering menu activities, bypassing the locks of the standard dialer.
One of the most popular and reliable tools is the application MTK Engineering Mode. It is specially designed for devices powered by MediaTek processors. After installation and launch, the application automatically detects the chipset model and prompts you to enter engineer mode. The interface may be in English or Chinese, but navigation is intuitive thanks to icons.
Another useful application is Secret Codes or Hidden Settings. These apps contain a database of codes for thousands of device models. Not only do they try to open the menu with code, but they also provide direct links to hidden Android settings pages, such as Wi-Fi or Bluetooth test menus, that are hidden deep in the system.
The installation process is simple: download the application, provide the necessary permissions (usually access to the phone and device status) and press the “Enter Engineer Mode” button. If the device has restrictions (for example, on some versions of MIUI or EMUI), the application may request permission to display on top of other windows or access via ADB.
☑️ Preparing to install login applications
Setting up network and GPS through the engineering menu
One of the most popular functions of the engineering menu is setting up cellular communication parameters. In the section BandMode or Network Selecting you can force the phone to operate only with 4G (LTE), excluding switching to unstable 3G or 2G. This is especially true in areas of poor reception, where the phone constantly “jumps” between communication standards, draining the battery.
To improve navigation, you should go to section Location → Location Based Service. Here you can reset AGPS (Assisted GPS) data. This procedure clears the cache of the satellite almanac and loads current data on their position, which significantly speeds up the “cold start” of the navigator. Here you can also enable or disable the use of GLONASS, Beidou or Galileo satellite systems.
In the Audio section, volume levels can be adjusted. The parameter Volume allows you to separately adjust the gain for the “Headphones”, “Speakerphone” or “Talk” modes. Be extremely careful: increasing the values too much may cause the speaker to wheeze or cause physical damage due to overload.
How to change the network type manually? Go to Phone Information (via code 4636). Find the “Set Preferred Network Type” drop-down list. Select option LTE Only. Please note that in this mode, incoming calls may not go through unless VoLTE is enabled, as the 2G/3G network for voice communication will be disabled.
⚠️ Warning: Setting the “LTE Only” mode may result in you not being able to make emergency calls (112, 911) if your operator does not support VoLTE in your coverage area.
Forcibly changing the network type to “LTE Only” increases Internet speed, but may block the ability to make regular voice calls without VoLTE technology.
Possible risks and precautions
Working with the engineering menu is associated with certain risks. This is not an ordinary settings menu, where the maximum that threatens the user is resetting the wallpaper. This is where you interact with firmware and device drivers. Incorrectly changing IMEI, sensor calibration or radio module parameters can lead to the phone no longer seeing the SIM card or losing the ability to connect to Wi-Fi.
The section IMEIis particularly dangerous. Attempting to change or overwrite the IMEI without a compelling reason (such as crash recovery) is illegal in many countries and may result in your carrier blocking your device permanently. Modern smartphones have write protection, and an unsuccessful attempt can “brick” the modem.
It is also worth mentioning touchscreen calibration. If you accidentally mess up the sensor grid coordinates, your phone may become partially or completely uncontrollable. Restoring factory calibration without special equipment and service software can be extremely difficult. Therefore, before any experiments, make sure that you have the opportunity to make a full backup or rollback of the system.
If after your actions the phone begins to behave inappropriately (it gets hot, does not connect to the network, reboots), first of all, reset the settings to factory settings (Wipe Data). If this does not help, you will need to flash the device via a computer using the manufacturer's official utilities (Odin for Samsung, Mi Flash for Xiaomi, etc.).
Frequently asked questions (FAQ)
Is it safe to enter the engineering menu on Android 9?
Entering the menu itself safe. The only risk is changing the settings inside it. If you just look at the information (kernel version, battery stats), nothing bad will happen. Problems begin when writing new values to the configuration fields.
Why does the code ##4636## not work on my phone?
The manufacturer of your model may have blocked this code in the firmware. This is common on Samsung, Huawei and some Xiaomi custom builds. Try using third-party applications from Google Play, such as "Secret Codes" or "MTK Engineering Mode".
Is it possible to unlock the phone from the operator through the engineering menu?
No. The engineering menu is intended for diagnosing and configuring equipment, and not for software unlocking of network restrictions (Network Unlock). This requires special unlock codes from the operator or service equipment.
How to return the settings if I messed something up?
Try to find the "Default" or "Reset" item in the same section where you changed the settings. If this does not help, perform a complete factory reset of your phone via the Recovery menu. In extreme cases, you will need to flash the device.
Are root access needed to enter the engineering menu?
In most cases, root access is not required to enter via USSD codes or special applications. However, to change some deep system parameters (for example, rewriting IMEI or changing processor frequencies), superuser rights may be required.