Managing mobile connections in Xiaomi, Redmi and POCO smartphones is often a question for users, especially when it comes to non-standard use cases: a situation where only one physical SIM card is installed in a device and the user wants to turn it off software is less common than managing double tariffs, but has its own important technical nuances. Deactivation of the communication module may be necessary to save battery power in areas of poor coverage or to force switch to Wi-Fi Calling.
With MIUI and the new HyperOS, the logic of network interfaces is designed to ensure maximum stability of communication. However, the settings interface is not always obvious, especially if the second slot is empty. Many users get lost without finding the familiar switchboard for the only active slot. Understanding the architecture of the Settings menu will help avoid unnecessary actions and resetting to factory settings.
In this article, we will discuss in detail the algorithms for disabling a SIM card when it is physically present in a single instance, we will look at standard methods through the system menu, the use of engineering codes for diagnostics and specific settings for different versions of firmware, and will also discuss why the button may not be available and how this affects the operation of the mobile Internet and voice calls.
Standard algorithm through the settings menu
The most secure and recommended way to manage SIM cards is to use the operating system’s standard interface. Regardless of how many cards are installed in the device, the system aims to give the user full control over each slot. To access these options, you need to go to the Settings section, which is usually represented by a gear on the desktop or in the notification curtain.
The path may vary slightly depending on the version of the shell, but the overall structure is maintained. You'll need to find a point responsible for connecting and transmitting data "SIM-maps and mobile networks. "" This is where all the key switches that control the phone's radio module are concentrated.
- 📱 Open the main menu and select "Settings".
- 📶 Go to section "SIM-maps and mobile networks".
- 🔌 Find the "Use" switch. SIM-Map opposite the image of your operator.
- ✅ Confirm the action in the pop-up window if the system requests confirmation.
If only one SIM card is installed in the phone, the interface may behave specific. In some cases, the system automatically hides the common switchboard if only one slot is active, assuming that the user always needs communication. However, when you enter the settings of a particular slot in detail (usually a clickable area with the operator's name), the activation / deactivation option should be available. Important: disabling the single SIM card completely breaks the connection to the cellular network, making incoming calls and SMS impossible.
☑️ Pre-switch check
Features of the interface in MIUI and HyperOS
Xiaomi shells are known for their deep customization, which sometimes leads to changes in the location of controls. In versions of MIUI 12, 13, 14 and the latest HyperOS, the logic of the settings grouping has changed. Users may find a situation where the switch is not in a visible place, but hidden in the submenu or requires additional actions to activate.
Unlike pure Android, where settings are often linear, MIUI uses a tree-like structure. If you don't see the switch on the home screen of SIM card settings, try clicking on the operator name or SIM card icon. This action should open a detailed menu where settings of the preferred network type, roaming and, of course, slot activation are available.
| Shell version | Location of the menu | Nuance of management |
|---|---|---|
| MIUI 12 / 13 | Settings -> SIM-maps and mobile networks | Direct access to the tumbler |
| MIUI 14 | Settings -> Connections and Sharing | Entry to slot settings is required |
| HyperOS | Settings -> Mobile Network | Grouping by operator |
| Global ROM | Settings -> Network and Internet | Standard Android Interface |
It is worth noting that in Chinese versions of the firmware (CN ROM), which are often recast on the global or used with installed Google Play, the terminology may differ "SIM-The term "Dual" may be used. SIM settings" or "Mobile Network" even if the slot is physically single. In such cases, it is useful to use a search by settings by entering a request "SIM" or "Mobile".
Why does the switch disappear?
Use of engineering menus and codes
For advanced users who find standard methods to be ineffective or if the interface is not working properly, there is the possibility of managing communication modules through an engineering menu, a hidden part of the system designed for testing equipment by plant engineers. Access is provided through a set of special USSD-codes in the appendix "Telephone".
The most common code to access modem testing on MediaTek and Qualcomm devices (which are used in most Xiaomi smartphones) is ##4636##. Once you type this code (without a call button), the Testing menu should automatically open. If the code does not work, it is possible that your firmware version will block access to this menu for security or stability reasons.
In the menu that opens, you need to select "Phone Information" and display detailed signal and network management statistics. To turn off the SIM card, you need to find a drop-down list or switch called "Set Preferred Network Type" or "Radio Power." The change in the status of the radio module here is a hardware shutdown, which may be more useful than software-based shutdown emulation.
⚠️ Warning: Changing the settings in the engineering menu without understanding their purpose can lead to network loss, inability to make emergency calls or incorrect operation. 4G/5G Be very careful and only change the settings associated with the radio on/off (Radio Power).
Alternative methods: Air mode and profiles
If your goal is simply to temporarily disconnect from the cellular network, you don't have to look for specific settings to disable the SIM card. The fastest way is to activate flight mode, which is a method that forcibly jams all the RF radiation of the smartphone, including Wi-Fi, Bluetooth and cellular communication.
However, flight mode often turns off Wi-Fi, which can be inconvenient if you want to stay online via a router, but disable the SIM card. In this case, you can use automation scenarios or third-party applications, but MIUI has a built-in Mode feature. By creating a guest or sleep scenario, you can set up an automatic shutdown of mobile data and voice calls, leaving the SIM card formally on but inactive for traffic.
- ✈️ Flight mode: completely disables all radio modules, including SIM card.
- 🔒 Do Not Disturb: Blocks only sounds and notifications, but communication remains active.
- 📉 Disabled data: leaves SIM card on for calls, but blocks the internet.
- 🤖 Scenarios: Automates the switching of settings on a schedule or geolocation.
The use of power saving modes can also affect the operation of the SIM card. In the "Ultra-energy saving" mode, the system can restrict the background activity of network services, which actually leads to a temporary "falling asleep" of the communication module, although formally the SIM card remains active in the system.
Display problems and interface bugs
Users of Xiaomi smartphones periodically encounter software errors when the settings interface stops displaying the current state of the SIM card. For example, the switchboard may be gray (inactive), or after trying to turn off the SIM card continues to show the presence of the network. This is often due to the freeze of the system process ril-daemon (Radio Interface Layer), which is responsible for the interaction of the software and modem.
One common reason is the settings conflict after a firmware update. If you upgrade from MIUI 13 to MIUI 14 or HyperOS, the old configuration files may conflict with the new interface rules, in which case a simple reboot of the device often doesn't help, as the network settings cache is saved.
To solve the problem, try resetting your network settings. This action will not delete your personal files, photos or apps, but will return all connection settings (Wi-Fi passwords, Bluetooth settings, APN and SIM card settings) to factory values. The path to this feature is usually in Settings -> Connection and Sharing -> Reset Wi-Fi, mobile networks and Bluetooth.
⚠️ Warning: Before performing a network reset, be sure to write down passwords from important Wi-Fi networks, as they will be deleted. PIN-SIM card code, if installed, as after reset, the phone can request it again at the first registration in the network.
The impact of the disconnect on the work of the smartphone
Disabling a single SIM card has a number of implications for the device, primarily for phone-related services. Android security and banking applications can use SMS to confirm transactions. If the SIM card is disabled software, incoming SMS with confirmation codes will not arrive, which can block access to online banking or instant messengers.
In addition, some MIUI features, such as Find a Device or synchronize contacts with a Mi Account, can behave unpredictably when the SIM card status is switched frequently, and the system may view the abrupt disappearance of the network as a hardware failure and start to use the battery more aggressively in attempts to restore the connection, even if you have disabled the SIM card yourself.
It's also worth mentioning the impact of location. GPS-The module is autonomous, the technology A-GPS It uses cell tower data for a quick start (cold start) and when the SIM card is turned off, it can take longer to determine the coordinates, especially in urban environments with high density of buildings, where the signal is GPS reflect off buildings.
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If you need to switch your SIM card to Wi-Fi only mode frequently, consider using quick setup widgets or application shortcuts that allow you to toggle your mobile network in one click, bypassing the deep settings menu.
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Software-based deactivation of the SIM card is a temporary measure. To completely isolate the device from cell towers (for example, to protect against IMSI-catcher or radiation), software methods are not enough, it requires the physical extraction of the card or the use of a Faraday case.