How to disable VoLTE on Xiaomi Mi 9T: the full guide

The Xiaomi Mi 9T, also known as the Redmi K20 in the Chinese market, has long been considered a benchmark for performance in the mid-range segment. However, despite its powerful processor and high-quality build, users are periodically faced with software nuances in the operation of cellular communication. One of the most frequently discussed issues is Voice over LTE technology, which in some regions or under certain conditions of the operator can cause failures.

Device owners often set out to force this feature to stabilize voice communication or solve problems with switching between 4G and 3G. Standard system settings do not always provide direct access to the desired switch, which forces us to look for deeper methods of interfering with the modem.

It is important to understand that disabling VoLTE can affect the sound quality during a conversation, returning it to the standards. HD Voice or regular GSM-It's a codec, but it often eliminates call cliffs. Before you start any manipulation, you should weigh the pros and cons, as modern operators are increasingly adopting VoLTE support.

Why is it necessary to disable VoLTE?

The fourth generation voice technology is designed to improve communication quality, but in practice, the implementation of MIUI in the firmware sometimes works poorly. Xiaomi Mi 9T users can observe a situation when the phone “hangs” in LTE mode, but incoming calls do not pass, or the interlocutor does not hear the user. These are classic symptoms of conflict between the software of the smartphone and the equipment of the operator’s base station.

Another common reason for the failure is increased battery consumption. Constant search and retention of a 4G signal for voice traffic can significantly reduce battery life, especially in areas of uncertain reception. In such cases, forced switching the phone to 3G mode for calls becomes the only way to comfortably use the device during the day.

⚠️ Warning: Disabling VoLTE can cause the phone to automatically switch to the network during a conversation 3G or 2G. If your location is not catching well 3G, The quality of the communication may deteriorate.

It is also worth mentioning the specifics of the two SIM-In Dual mode. SIM Activation of VoLTE on one card can block the work 4G Second, leaving it in mode. EDGE. This is a hardware platform limitation that often annoys users who need fast internet on both SIM cards at the same time. 4G secondary.

Verification of operator support

Before you get into system settings, you need to make sure that the problem lies in the phone, not in the services of the operator. Many users try to disable VoLTE, although the root of the problem lies in the lack of activated service on the provider side. In the Xiaomi Mi 9T, the indication of the icon “HD” or “VoLTE” in the status bar can appear even without real support from the network.

First, you should visit your mobile operator’s personal account or contact technical support. USSD-Without this step, any manipulation of the smartphone menu may be useless, since the network will simply not accept requests for a voice channel through the operator’s application. LTE.

• 📱 Check for a VoLTE icon or HD in the status bar with the mobile Internet enabled.
• 📞 Call the operator support and check if VoLTE is activated on your number.
• 🔄 Make sure the latest version of the firmware is installed. MIUI for your region.
• 🌐 Check if the mobile internet is working during an incoming call (if VoLTE is active, the internet should not be shut down).

It's important to consider that even with carrier support, in some regions, 4G coverage can be unstable for voice calls, in which case the phone will constantly try to establish a connection over LTE, lose it and search the network again, which creates a "twitch" effect, which is where manual control of network modes helps.

Basic settings through the smartphone menu

The easiest and safest way to manage networking features is the standard Android settings menu. In the MIUI shell, the path to these options may vary slightly depending on the firmware version (Global, China, Russia), but the logic remains the same. First, try to find the switch in the visible part of the interface.

Go to Settings section, then select a paragraph. SIM-You have to choose a specific SIM card that you want to change, and if you have a service and a region that supports the function, you have to have a VoLTE switch that will force voice calls to the network to be turned off. 3G/2G.

However, owners of Xiaomi Mi 9T often face a situation where this item is simply not on the menu, this may be due to the fact that the firmware is not certified for a specific operator, or hidden by a software limitation of the region, in which case standard methods will not work, and you will have to resort to the use of engineering menus or special codes.

Using the Engineering Menu to Disable

If the standard interface doesn’t provide the right options, the engineering menu comes to the rescue, a hidden part of the system designed for testing equipment, accessed on the Xiaomi Mi 9T through a set of special code in the Phone application, which requires care, since changing the wrong parameters can affect the operation of the radio module.

To enter the diagnostic menu, dial the combination ##6484## or #4636##. The second combination often leads directly to the testing menu, where you select Phone Information.

In the list that opens, find VoLTE Provisioned or Enable VoLTE. Unchecking the box or switching the switch to False disables the feature on the modem level. Immediately thereafter, the 4G/LTE icon may disappear for a second and reappear again, but voice calls will now be initiated over 3G.

⚠️ Note: In the engineering menu, do not change the values of parameters you are not sure about. Resetting the radio module can lead to temporary loss of signal or the need to flash the device.

It is worth noting that on some versions of Android (especially Android 10 and 11 in MIUI 12/13) access to this menu through codes can be blocked by developers, in which case the system simply ignores the code input or opens the standard settings menu, a security mechanism that requires the use of alternative methods, such as third-party applications.

Application of third-party applications and hidden codes

When MIUI's built-in tools block access to the necessary features, the Play Market's dedicated utilities come to the rescue. Applications like 4G Switch or Force LTE Only (4G/5G) allow you to manage network priorities without deep implementation, using the same hidden APIs as the engineering menu, but providing a user-friendly interface.

To use such applications on the Xiaomi Mi 9T, you often need to provide special permissions through the ADB (Android Debug Bridge) if the application can not get them automatically. However, many simple switches work without root rights, simply sending hidden commands to the system, which makes them safe for the average user.

Special attention should be paid to the application Force LTE Despite the name, it often allows you to do more than just 4G, On the contrary, it is forbidden to use LTE Forcing the phone to use 3G For calls. In the application interface, you need to find the Method section. 2 (Android 11+) Or similar to your version of the OS, and choose the mode LTE/TD-SCDMA/UMTS/GSM, excluding VoLTE if such option is available in the list.

Management through ADB-team

For advanced users who were not helped by previous methods, there is the most powerful tool – debugging. USB And you can type commands through a computer. This is guaranteed to work on the Xiaomi Mi. 9T, Because it allows you to interact with the system at a level that is not available for conventional applications, USB-cable and installed drivers ADB.

First, you need to activate the developer mode. To do this, quickly click on the build number in the About Phone section seven times. Then turn on "Debugging by USB" in the Developer menu. Connect the smartphone to your computer and enter a command in the command line to check the connection:

adb devices

Once the connection is confirmed on the phone screen, you can enter a command that forcibly disables VoLTE support in the modem configuration. The specific command may vary depending on the Android version, but often the following request is triggered via shell:

adb shell settings put global volte_enabled 0

⚠️ Attention: Teams ADB You only enter the commands you found in the verified sources for your model.

If the command is successful, the changes take effect immediately. Rebooting the device is not required, but is desirable to anchor the result. This method is especially useful when the MIUI interface hides all the switches and the engineering menu is locked. Once you turn off, you will notice that the phone has stopped displaying the HD icon when calling.

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If the Internet disappeared during a conversation after the VoLTE shutdown, it is normal for 3G networks. To return the Internet, turn on the access point in the settings or use Wi-Fi.

Frequently Asked Questions (FAQ)

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Disabling VoLTE on Xiaomi Mi 9T is an effective solution for areas with unstable 4G coverage, which allows you to avoid missed calls and save battery power.