Modern smartphone users are often faced with a situation where the device stubbornly holds the signal 3G or H+, ignoring the available fourth-generation towers. This leads to slow loading of pages, buffering of videos and the inability to comfortably use the navigator in real time. There can be many reasons: from temporary failures in the operator’s work to specific firmware settings that limit the choice of network.
The solution to the problem usually lies in forcibly switching the modem operating mode. Standard interface settings do not always provide this option, especially on budget models or devices with reduced functionality. In such cases, you have to turn to hidden menus or use special engineering codes that allow you to directly control the radio module of your smartphone.
In this article we will analyze in detail all the legal and safe ways to fix the network on LTE. You will learn how to bypass the system's software limitations, what risks are associated with a forced change of communication standard, and how to return everything back if the connection is completely lost. The instructions cover both standard methods through settings, as well as advanced methods for experienced users.
Standard network settings and selection of connection type
The first and most obvious step is to check the basic settings in the settings menu. In most cases, the system itself selects the optimal mode, but sometimes this algorithm fails. You need to go to the section Settings → Connections → Mobile networks. Here you should find the item “Network mode” or “Preferred network type.”
If there is no item in the list of available options LTE/3G/2G (auto) or similar, this may indicate that the SIM card does not support 4G, or there is no coverage in the area. However, if there is such an item, but the phone still does not switch, try manually selecting the mode LTE only. This will force the modem to ignore all other standards.
It is worth considering that on some devices with two SIM cards, 4G functions are available only for one slot. Check which card is assigned for data transfer by default. Sometimes simply moving the SIM card to another slot solves the problem without using complex manipulations.
⚠️ Attention: Forced selection of the “LTE Only” mode can lead to a complete loss of voice communication if your operator does not support VoLTE technology. You will be able to use the Internet, but incoming and outgoing calls will not be available.
After changing the settings, it is recommended to turn “Airplane Mode” on and off for 10-15 seconds. This action initiates re-registration of the device in the operator’s network with new parameters. If the icon 4G or LTE appears, then the problem has been resolved at the software interface level.
If after a reboot the phone resets to 3G again, try removing the SIM card, wiping the contacts with an eraser and inserting it back - oxidation of the contacts often causes network detection errors.
Using the engineering menu to fix the network
When standard settings do not give the desired result, the engineering menu comes to the rescue. This is a hidden section of the system intended for testing equipment by manufacturing plant engineers. It is accessed through a set of special USSD codes in the “Phone” application.
For most processor-based devices MediaTek the universal code is ##3646633##. For devices on Qualcomm the code ##4636##often works. After entering the combination, you will be taken to the service menu, where you need to select the section Phone Information or “Phone Information”.
In the window that opens, find the drop-down list with the name Set Preferred Network Type. This is where network priorities are managed. You need to select a value containing the abbreviation LTE. The most stable option is usually LTE Only or LTE/TD-SCDMA/WCDMA/GSM.
- 📱 LTE Only —hard fixation only on 4G, calls may not go through without VoLTE.
- 📡 LTE/WCDMA/GSM —4G priority, but with the ability to roll back to 3G and 2G for calls.
- 📶 WCDMA Only —forced 3G, useful in areas of poor 4G reception for voice stability.
- 📞 GSM Only —only 2G, maximum signal range, but minimum Internet speed.
After selecting the desired item, the changes take effect instantly. Please note that the engineering menu interface may differ depending on the version Android and shell of the manufacturer (MIUI, OneUI, ColorOS). If one code does not work, try alternative combinations specific to your brand.
What to do if the codes do not work?
On new versions of Android (11, 12, 13 and higher), access to the engineering menu via USSD codes is often blocked by the manufacturer for security reasons. In this case, you will need to use third-party applications or connect to a PC.
Secret codes for different smartphone manufacturers
Each major electronics manufacturer has its own unique combinations for accessing hidden functions. Knowing these codes allows you to quickly diagnose the problem and switch the modem’s operating mode without installing additional software.
Below is a table with the most relevant codes for popular brands. Please remember that on some models these functions can be software disabled by the telecom operator or the firmware itself.
| Brand / Manufacturer | Access code | Purpose |
|---|---|---|
| Samsung | *#0011# |
Service Menu (Service Mode) |
| Xiaomi / Redmi | ##4636## |
Testing and information |
| Huawei / Honor | ##2846579## |
ProjectMenu (network settings) |
| Sony | ##7378423## |
Service Info |
| Meizu | ##3646633## |
MediaTek engineering menu |
For owners Samsung the process may vary. In the service menu *#0011# you need to press the menu button (three dots or a physical button), select Back, then Key Input and enter the code Q0. After this, an extended menu will open where you can select Band Selection and tick the required frequencies LTE.
If your phone was released recently, the likelihood of blocking these codes is high. In such situations, the system may simply display a connection error message or do nothing when entering numbers. This is not a breakdown, but a deliberate limitation on the part of the developers.
Advanced methods through applications and ADB
If the built-in access tools are closed, you can use third-party utilities from the store Google Play. Applications like Force LTE Only (4G/5G) or NetMonster create a shortcut to the hidden system testing menu, which is usually inaccessible to the user.
By downloading such an application, you get direct access to the page phoneinfo. The app interface duplicates the functions of the engineering menu: here you can change the network type, view the signal level in dBm and find out the ID of the nearest tower. This is especially convenient, since it does not require memorizing complex digital combinations.
For the most advanced users, there is a method of debugging via a computer using the tool ADB (Android Debug Bridge). This method requires enabling USB debugging in the developer menu and connecting the smartphone to the PC. The command for forced switching looks complicated, but it is most effective.
adb shell service call phone 3 s16 "preferred_network_mode" i32 9Here the number 9 corresponds to the mode LTE Only for most devices. By changing this number, you can switch between other standards. However, using ADB requires caution: an incorrect command can lead to unstable operation of the radio module.
⚠️ Attention: The use of third-party applications and ADB commands is at your own risk. Incorrect interference with the operation of the radio module may require resetting the network settings to factory settings.
☑️ Preparing to use ADB
Possible problems and ways to solve them
After forcing the mode installation 4G users may encounter a number of non-obvious problems. The most common of them is loss of voice communication. This happens because in LTE Only mode the phone cannot “fall” to 3G or 2G to make a regular call if the operator does not provide VoLTE service.
Another problem is rapid battery drain. When searching for a network in conditions of unstable 4G coverage, the modem consumes significantly more energy than in automatic mode. If you are outside the city or in a building with thick walls, the phone will constantly scan the airwaves in attempts to find a stable fourth-generation signal.
A complete loss of communication is also possible if 4G towers in your area are temporarily turned off for maintenance or are located too far away. In this case, the phone will show the status “No network” or “Emergency calls only,” although there may be a strong 3G signal nearby, which is ignored by the settings.
- 🔋 Fast discharge —return to “Auto” mode when the battery is low.
- 🚫 No calls —check VoLTE support with your operator or switch to 3G.
- 📉 Low speed —the tower may be overloaded, try changing the frequency range.
- 🔄 Reset settings —after rebooting, the phone may return to automatic mode.
To solve these problems, it is enough to temporarily return the settings to “Auto” or “3G/2G/4G”. If the problem is the lack of VoLTE, you can try to activate this function through the engineering menu by finding the item VoLTE Provisioned and checking the box.
Forced 4G mode is a temporary measure to improve Internet speed, and not a permanent setting for everyday use, especially in areas of poor reception.
How to return automatic selection networks
If experiments with the network have led to unstable operation or you just want to return everything as it was, the return procedure is quite simple. The most reliable way is to use the same tool you used to enable the commit. Go to the engineering menu or assistant application.
In the item Set Preferred Network Type select the option containing the word Auto or listing all standards, for example LTE/TD-SCDMA/WCDMA/GSM (auto connect). This permission will allow the modem to independently select the best available communication standard at the current time.
In some cases, changes are not applied immediately. Then you need to completely reboot the device. If this does not help, you can use the network settings reset function. It's in the menu Settings → System → Reset settings → Reset Wi-Fi, mobile settings. Internet and Bluetooth.
This operation will delete saved Wi-Fi passwords and Bluetooth device settings, but will return the factory settings of the cellular module. This is guaranteed to get rid of any software locks manually installed by the user.
⚠️ Attention: Resetting network settings does not delete your personal files, photos or contacts. However, you will have to re-enter passwords for wireless networks and pair your watch or headphones.
After returning to factory settings, the phone will start searching for the network again. In the first minutes, signal instability is possible, as the device scans all available frequencies. Usually after 5-10 minutes the connection stabilizes.
Why do the settings reset themselves?
Telecom operators can send special OTA commands (Over-The-Air), which force the network settings to return to the recommended values when re-registering in roaming or after updating the profile.
Is it safe to use the engineering menu?
Yes, using the engineering menu to change the network type is safe as long as you do not change the transmitter power or antenna calibration parameters. Returning to factory settings is always possible through the reset menu.
Why did the Internet disappear after turning on 4G?
Perhaps the selected 4G tower does not have Internet access for your tariff, or APN access points are not configured. Check the access point settings in the mobile networks menu.
Does 4G fixing affect the phone's radiation?
The radiation level is regulated by safety standards and does not depend on the selected network mode. However, in conditions of poor signal, the phone increases the transmitter power, which can slightly increase energy consumption.
Is it possible to enable 5G using the same methods?
The principle is the same, but in the list of networks you need to select options marked NR (New Radio). However, 5G support depends solely on the presence of an appropriate modem in your smartphone.
Does this method work on dual-SIM phones?
Yes, but you need to switch the mode for each slot separately, if the menu allows it. Often the second slot only works in 2G/3G mode, regardless of the settings of the first.