Modern Xiaomi smartphones running on the shell of MIUI or the new HyperOS, by default, tend to use the maximum available connection speed, switching between 4G and 5G where possible. However, in the realities of remote regions or when driving in transport, there is often a situation where the LTE signal is unstable, “jumps”, and the Internet actually does not work, although the indicator shows the presence of a network. In such cases, the only right solution is to force the switch to a more stable, albeit less fast 3G standard (WCDMA).
Not only can the phone need to lock in this mode be due to poor coverage, but some users are specifically looking for a way to turn on the phone. 3G Xiaomi to save battery life, as a constant signal search 4G In the area of its uncertain reception, the battery quickly discharges. SIM-Cards or tariffs that do not fully support modern data protocols.
In this guide, we’ll take a look at all the available methods, from standard settings on the menu to using hidden engineering codes, learn how to get around the limitations of the interface if the standard slider doesn’t work, and how to properly configure access points for maximum connection efficiency.
Why is your smartphone losing 4G and when you need 3G?
The problems with the coverage of fourth-generation networks are often local, and operators may be doing technical work, or the terrain creates "dead zones" for the high frequencies on which LTE operates. In this situation, the phone starts frantically switching between 4G, 3G and even 2G, trying to find a stable signal, a phenomenon called handover, and it has a huge negative impact on the quality of communication.
Forced imposition of the regime 3G only WCDMA The only solution to this problem is drastically. The smartphone stops scanning the airwaves in search of LTE-It's a tower, and it's a stable connection to the nearest second-tier base station:
- 📶 The area of country cottages and rural areas, where towers 4G They're far apart.
- 🚗 Movement in a car or train when the speed of changing towers is too high for stable driving LTE.
- 🏢 Basement rooms and deep floors of buildings where high frequencies LTE They don't break through thick walls.
⚠️ Attention: Compulsory inclusion 3G completely disable the use of VoLTE (calls through the 4G). If your company does not support the technology CSFB (return 3G for voice calls, you may find it impossible to make calls while only using the Internet.
Also, consider that data transfer speeds on third-generation networks are limited. If you want to download a heavy app or watch video in 4K, you should still look for a zone with stable LTE. However, for instant messengers, navigation and voice calls, 3G often turns out to be even more reliable than “blinking” 4G.
Standard method of switching through settings SIM-map
The easiest and safest way to change the type of network is to use the standard MIUI interface. In most cases, the system itself correctly processes the user's request, but sometimes the menu can be hidden or called non-standard depending on the firmware version (Global, Chinese, Russian).
First, you need to go to the basic settings of the device. Find the partition responsible for connections. The path may differ slightly, but the logic remains the same: → SIM-You'll see a list of SIM cards installed here. You'll see the one you want to go online.
Within the menu of a particular SIM card, find Network Type (or "Preferred Network Type"). Clicking on it will open a list of available options. The standard set usually looks like this:
- 🔹 Preferably. 5G (if supported by the model).
- 🔹 Preferably. 4G (LTE).
- 🔹 Preferably. 3G (WCDMA).
- 🔹 Only 2G (GSM).
Select Preferably 3G. The system can warn you that Internet speeds will slow. Confirm. If you have a 3G or H+ icon in the status bar after that, then the method worked. However, on newer versions of Android and MIUI, developers often hide the option of choosing 3G only, leaving only automatic mode.
☑️ Checking network settings
If there is no 3G item on the list, but only “Preferably 4G/3G/2G”, then the standard means of fixing the network will not work, in which case you will have to resort to more advanced methods described below.
Xiaomi Engineering Menu: Hidden Codes for Network Selection
When a standard menu fails, the Engineering Mode comes to the rescue, a diagnostic interface hidden from ordinary users that allows you to control the modem parameters at a low level, and this is where you find a switch that fixes the communication standard rigidly.
Special menus must be used to enter the menu USSD-Note that you need to type code through the Phone app as if you were dialing a number, and the codes may vary depending on your smartphone's processor (Snapdragon or MediaTek).
Try entering the following combinations:
- 🔢 ##4636## - Universal Android code for the test menu.
- 🔢 ##3646633## - often runs on MediaTek processors.
- 🔢 ##6484## - an alternative for some models.
Once you enter the last digit (#), the menu should open automatically. If you see the list of options, look for the Phone Information section. There may be several of them (Phone Information 1, Phone Information 2) - choose the one that matches your SIM card.
⚠️ Warning: Be extremely careful in the engineering menu. Changing unknown parameters can cause the radio module to malfunction or the network to disappear completely).
Inside the section, find the drop-down list of Set Preferred Network Type. Open it up and select WCDMA only (3G only) or WCDMA preferred. Communication should restart and the phone will go to 3G mode. If the list is inactive (gray), it may be blocked by the provider or root access is required.
What do I do if the codes don't work?
Use of Xiaomi.eu app and third-party utilities
If embedded tools are blocked, third-party tools come to the rescue. One of the most popular solutions for Xiaomi owners is to use the capabilities of custom firmware Xiaomi.eu or specialized applications that require superuser rights (Root).
Xiaomi.eu (as a custom firmware) often has an extended menu of hidden features available through code ##6484## or in a special settings section. However, for users of stock MIUI, utilities like MTK Engineering Mode (for MediaTek processors) or Force LTE Only (4G/5G Switch) are more relevant.
Working with such applications is usually based on the following algorithm:
- Download and install the app from a trusted source (Google Play or 4PDA).
- Launch the program and provide the necessary permissions.
- Go to MTK Settings (or similar) section.
- Select BandMode or Network Mode tab.
- Uncheck LTE and 5G, leaving only WCDMA (3G).
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If you don't have Root rights, some applications can run in ADB mode, which requires connecting your phone to your computer, enabling USB debugging, and entering an activation command via your PC, which is more difficult, but safer, to get full access to the system.
It is important to understand that third-party apps may not work on the latest versions of Android (12, 13, 14) due to Google’s security policy strengthening. ADB-team.
Configure APN Access Points for Stable 3G
Even if you have managed to force 3G on, the internet may not work or work slowly due to incorrect access point (APN) settings. carriers often have separate settings for 2G/3G networks that differ from the settings for 4G.
To check and change these settings, go down the path: Settings → SIM-maps and mobile networks → (Your SIM card) → Access points (APN). In the upper right corner, press the menu button (three dots) and select Reset to default.
If the automatic setup didn’t help, create a new access point manually:
| Parameter | The value for 3G (example) | Note |
|---|---|---|
| Name. | Internet 3G | Any convenient name |
| APN | Internet (or mts, beeline, etc.) | Critical parameter |
| Type APN | default,supl | No gaps. |
| Protocol APN | IPv4/IPv6 | Better leave mixed. |
Once you create or edit the access point, be sure to save it (via the menu) and activate it by ticking next to the name.
💡
APN settings often solve the problem of “the Internet is there, but the pages are not loaded” even when the network is fully signaled. Always check this setting when changing modem mode.
Diagnosis of problems and frequent errors
During the setup process, users often encounter situations where the phone is “hanging” in network search mode or loses signal altogether, which can be caused by a conflict of settings or physical problems with the SIM card.
One common mistake is using an old SIM card cut out of the Mini or Micro format in Nano. Contacts may be damaged, or the chip may not work properly with modern communication modules in 3G mode. In this case, it is recommended to contact the operator's cabin for a free replacement of the SIM card with a new one.
Metallic or too thick protective cases can shield the signal, which is critical for 3G, which has less penetrating capacity compared to some 2G frequencies, but greater than 5G.
⚠️ Warning: If after all the manipulations, the phone shows “No Network” or “Emergency Calls Only”, return the network settings to Auto mode (LTE/WCDMA/GSM). There may be no signal in your coverage area at all. 3G from your carrier, and the phone simply can't connect to anything.
Remember that forced 3G is a temporary solution to improve stability. Once you get back into the 4G acceptance zone, remember to return the settings back to high internet speed.