How to turn on the second SIM-Map on the phone Xiaomi: all the ways and nuances

Double. SIM-The card in Xiaomi smartphones is not just a convenience, but often a necessity for those who share business and personal calls, travel between countries or save on tariffs of different operators. The phone doesn't see the card, doesn't let you choose the network, or ignores the slot altogether. In this article, we'll look at all the ways you can turn on the second one. SIM on Redmi devices, POCO and Mi, including hidden settings MIUI, Solving common mistakes and tips for optimizing the performance of two cards at the same time.

It’s important to understand that the activation process can vary depending on the smartphone model, the MIUI firmware version, and even the region of the device purchase. For example, global versions of Xiaomi often support Dual SIM better than Chinese versions, where the second slot is sometimes locked software. We took all these nuances into account and prepared a universal guide that will help even if standard methods do not work.

Checking the compatibility of your Xiaomi with Dual SIM

Before you try to activate the second line, make sure your smartphone physically supports two. SIM-Some Xiaomi models (especially the flagship or older series) may have a hybrid slot, where the second connector is combined with a microSD card. SIM, or additional storage.

To check the type of slot:

• 🔍 Check the tray for SIM-If it has two chips, it is a full-fledged Dual. SIM. If one chip + MicroSD – Hybrid Slot.
• 📱 Go to Settings. → The phone. → Characteristics and find the line "Dual" SIM". In global firmware it is usually there, in Chinese it may not be.
• 🛠️ Use the Kimovil service by entering your Xiaomi model – it specifies the type of slot and supported standards (4G/5G each SIM).

Critical detail: Xiaomi 12T Pro, Xiaomi 13 Ultra and some other flagships after 2022 can only support Dual SIM in global firmware versions. Chinese modifications (with the C suffix in the name) often have a software lock of the second slot.

⚠️ Note: If you bought Xiaomi in China or on AliExpress without official localization, the second slot can be blocked even with physical support of Dual. SIM. In this case, you will need to re-flash to the global version. MIUI.

Standard way to activate the second SIM through settings

If your smartphone supports Dual SIM, the easiest way to enable the second line is through the standard settings menu, which works on most Redmi, POCO and Mi models with MIUI 12 firmware and later.

Step-by-step:

1. Put both in. SIM-cards in the respective slots (usually) SIM 1 - basic, SIM 2 - additional).
2. Go to Settings. → SIM-maps and mobile networks.
3. Tap on the second. SIM-map (it can be displayed as a map "SIM 2" or "Inactive").
4. Turn on the switch Use the switch SIM-map.
5. Choose the network type: 4G (preferably), 3G or 2G (if 4G is not available).
6. Prioritize calls and SMS (you can choose “Ask Always” or set the basic SIM).

After activation, the second network indicator will appear in the status bar (usually with a number "2" next to the signal level).If the indicator does not appear, try restarting the phone or checking if the cards are inserted correctly.

Insert both cards into the correct slots (SIM 1 and SIM 2)

Make sure that the cards are active with the operator (not blocked)

Check the network coverage in your area

Update firmware MIUI last-minute-->

⚠️ Note: Some models (e.g. Xiaomi Mi 10 or Redmi) K40) activate SIM The main card can automatically switch to the 3G, even if it supports 4G. It's due to the hardware limitations of the communications module. 4G, Try to turn off the second. SIM, Restart your phone and turn it on again.

Activate the second SIM through the engineering menu (for power users)

If the standard method didn’t work and you’re sure the phone supports Dual SIM, you can try activating the second line through an engineering menu, which is suitable for devices with a second slot locked software (often found in Chinese versions of firmware).

Instructions:

1. Open the Phone app and type the combination: ##4636## This will open the testing menu.
2. Go to the tab Phone Information.
3. Scroll down to the Set preferred network type section.
4. Select SIM 2 and set your preferred network type (e.g. LTE only).
5. Go back to the main menu and select DSDS Information (Dual SIM Dual Standby).
6. Activate the switch for the second SIM.

If the second SIM doesn’t appear in the settings after these steps, try another way through the MTK Engineer Mode (for devices running MediaTek processors):

• Install the MTK Engineer Mode app from Google Play.
• Open it and go to MTK Settings → BandMode.
• Select SIM 2 and set the supported frequencies (e.g. for 4G: LTE Band 1/3/7/20 for Europe).
• Save the settings and restart the phone.

Solving problems with the second SIM: no network, registration errors

Even after successful activation, the second SIM can be unstable: it can go missing, fail to catch 4G, or give an error, "Registration failed": Here are the most common problems and their solutions:

If the second SIM doesn’t catch 4G, even though the carrier supports this standard, try the following:

1. Go to Settings. → SIM-maps and mobile networks → [Yours. SIM 2] → Type of network.
2. Select 3G Only or 2G Only, then go back to 4G again.
3. If it doesn’t help, install the APN manually (you can take the options on your operator’s website).

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If the second SIM You're constantly losing your network, try disabling VoLTE for it. → SIM-map → [SIM 2] → Call VoLTE and turn off the switch. Sometimes it helps stabilize the connection.

No network.

Not defined by map

4G is not working

Calls only go through the main SIM.

Another problem.-->

Features of Dual SIM on different models Xiaomi

Not all Xiaomi smartphones are equally good at working with two. SIM-Here are the key nuances for the popular series:

Redmi Note 11/12/13: Supports Dual 4G VoLTE, but when an active call is made on one SIM, the second one is temporarily disconnected from the network (hardware platform restriction), and these models can also experience faster battery discharge when using two cards.

POCO F/X Series: Optimized for Dual SIM, But on some firmware (especially Chinese) segunda SIM only works 2G. Reflashing to the European or Global Version MIUI.

Xiaomi 12/13 Series: Flagships support 5G+4G at the same time, but only in global versions. On Chinese firmware, the second SIM is often limited to 3G, even if 4G is supported hardware.

Redmi A series (budget): Here Dual SIM is implemented in a simplified scheme - both cards work only in 3G/2G, and 4G is available only on the main SIM.

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On models with a Qualcomm Snapdragon 8 Gen 1/2 processor (such as Xiaomi 12 Pro or Redmi K50 Gaming), the second SIM can automatically turn off when the processor is under high load (games, benchmarks), this is due to the redistribution of modem resources. There is no solution - a feature of the chipset.

How to Prioritize Calls and Mobile Internet

When both SIM-The cards are active, it is important to allocate priorities correctly so that you do not miss important calls and do not waste traffic from the wrong card. MIUI It is flexible, but not all users know about all the features.

Main settings:

• 📞 Priority of calls: Go to Settings → SIM-map → Priority SIM You can choose from here: "Always ask" (the phone will ask which phone to use). SIM ring); - "SIM 1" or "SIM 2” (automatic choice).
• 🌐 Mobile Internet: In the same menu, there's a section called "Mobile Data." Here you can choose which one you want. SIM It's going to be used to transmit data by default. Please note that if you have Modem Modem or Access Point enabled, the Internet will only go through the selected modem. SIM.
• 📩 SMS: Priority settings for messages are in Settings → Annexes → Communications → Settings SIM.

For convenience, you can assign different ringtones for each SIM:

1. Open Settings → Sounds and vibration → Call melody.
2. Select SIM 1 Call Melody and SIM 2 Call Melody.
3. Set different ringtones to immediately understand which card the call is coming to.

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If you travel frequently, set up automatic network selection for the second one. SIM. To do this, go to the Settings. → SIM-map → [SIM 2] → Select a network and turn on the option "Automatically", which will help to avoid manual search of operators in roaming.

Firmware on the global version to unlock the second SIM

If your Xiaomi is bought in China or has Chinese firmware (denoted by the C suffix in the model name, for example, the Redmi K50G C), the second SIM slot can be blocked software, in which case the only reliable way to activate the Dual SIM is to reflash the device to the global version of MIUI.

Step-by-step:

1. Check the current firmware version in Settings → About Phone → MIUI version. If it says "China" - Chinese firmware.
2. Download the official global firmware for your model from Xiaomi Firmware. Choose the Global or EEA (for Europe) version.
3. Unclose the downloaded file and move it to the phone’s root folder (not to folders!).
4. Go to Settings → About the phone → System update.
5. Slip on the three dots in the upper right corner and select Select a firmware file.
6. Specify the path to the downloaded file and confirm the installation.

After flashing:

• The phone will reboot and reset to factory settings (take backup in advance!).
• The second SIM must be automatically determined.
• If this does not happen, repeat the steps from the standard activation method.

⚠️ Note: Reflashing to the unofficial version MIUI (For example, custom builds like xiaomi.eu can lead to locking the device through Mi Account. Use only official global firmware from Xiaomi. Also note that after the firmware, unlocking the bootloader can fly if it was performed earlier.

FAQ: Frequent questions about the second SIM in Xiaomi