Users of modern smartphones often face the need to change communication settings, but the interface Android can hide the necessary options behind several menu levels. The question of how to enter the specialized SIM card menu becomes especially relevant when changing operators, manually setting up access points, or trying to unlock additional network functions. Standard settings often offer only basic functionality, while in-depth parameters remain inaccessible to the average user without special knowledge.
There are several legal and safe methods for gaining access to control the communication module. From standard paths in the system to the use of engineering codes, each method has its own characteristics and security limitations. In this article, we will analyze in detail the mechanisms of interaction with SIM card, explain the difference between the user menu and the engineering mode, and also warn against actions that can lead to blocking of the device.
Before making changes, it is important to understand that the SIM card menu is not a single object. This is a collection of settings scattered across different sections of the system and special service codes. Improper interference with the operation of the radio module can lead to loss of signal or the need to reflash the device, so you need to act carefully.
Standard SIM card settings in the Android system
Most tasks related to SIM card management are solved through the standard operating system settings menu. Developers Google and manufacturers of shells like One UI or MIUI brought the main functions to the surface for convenience. To get there, you need to open the “Settings” application and find the section responsible for connections.
Depending on the version Android, the path may differ slightly. Typically this is the “Connections”, “Network and Internet” or “SIM Card Manager” section. Here the user can rename the SIM card, select the default card for mobile data and manage roaming.
- 📱 Switch between 2G/3G/4G/5G modes to save battery or improve reception.
- 🔒 Install, change or cancel PIN code to protect the SIM card from unauthorized use.
- 📞 Setting up call forwarding and waiting for a second call through the system interface.
To access more subtle settings, such as selecting the preferred network type, sometimes you need to click on the name of the operator or the SIM card itself in the list. This will open an additional submenu where you can manually select the operating mode of the radio module if automatic network selection does not work correctly.
⚠️ Attention: Changing the network mode to “2G Only” or “3G Only” may lead to a complete lack of voice communication in regions where operators have already disabled old communication standards. Use these settings for diagnostics only.
If the “Preferred network type” item is not in the menu, try turning on airplane mode for 10 seconds and turning it off - sometimes this refreshes the list of available options.
Using USSD codes and service commands
One of the fastest ways to enter the SIM card service management menu is use USSD requests. These are special commands that are entered through the Phone application as a regular number. They are sent directly to the telecom operator’s server and allow you to manage services without access to the Internet.
Each mobile operator has its own set of codes for checking the balance, connecting tariffs and managing services. However, there are also universal commands that work at the device or GSM standard level. For example, the command *#06# allows you to instantly find out the IMEI of the device, which is critical when checking the legality of the device.
*#06# - IMEI check ##4636## - Testing menu (does not work on all models)
**04*PIN*NewPIN*NewPIN# - Change PIN code
Command ##4636## deserves special attention, as it opens the hidden “Testing” menu. In this section you can find battery usage information, usage statistics and most importantly the phone information menu. This is where the settings for the preferred network type and switching between SIM cards in devices with two slots are often hidden.
⚠️ Attention: On Xiaomi, Huawei and some Samsung smartphones, this command may be blocked by the manufacturer. In this case, you will need to install a special launcher application or use ADB commands to activate the menu.
What to do if the code does not work?
If entering a combination of numbers does not bring up the menu, your firmware may be blocking this access. Try installing the “Force LTE Only (4G/5G)” application from the Play Market - it creates a shortcut to this hidden menu on the desktop.
Engineering menu and hidden radio module settings
For advanced users involved in signal optimization or repair, there is a concept engineering menu. This is a deep level of settings intended for service center engineers. Entry here is carried out through specific codes, which vary depending on the device processor (MediaTek, Qualcomm, Exynos).
On devices with a processor MediaTek the code often works ##3646633##, which opens the full engineering menu. In the “Telephony” section you can find the BandMode settings, where you manually select the frequency ranges on which the phone will operate. This is useful in areas of uncertain reception when the phone is constantly jumping between towers.
Devices based on Qualcomm can use the code ##7262626## to verify field tests, although the functionality here is often limited to signal monitoring. It is important to understand that changing parameters in the engineering menu without understanding the physics of radio waves can lead to the phone no longer seeing the network at all.
- 📡 Manual selection of frequency ranges (Band Locking) for fixation on a specific tower.
- 🔊 Setting microphone and speaker gain at the software level.
- 📶 View detailed information about the signal level (RSRP, SINR) in real time.
⚠️ Attention: Never press the “Set” or “Save” button in the engineering menu if you do not know exactly what a particular parameter is responsible for. Resetting the radio module to factory settings through the menu may require a visit to the service center.
Managing contacts and SIM storage
Another aspect of the “SIM card menu” that is often What users are looking for is managing contacts stored directly on the chip. In the era of synchronization with Google Account this function is becoming a thing of the past, but for migrating data from old phones it remains indispensable.
To enter this menu, you need to open the standard “Contacts” application, click on the three dots in the corner or the menu button and select “Settings” or “Manage contacts”. There will be an item “Import/export contacts”, where you can select the “SIM card” source.
Modern versions of Android often limit the number of characters in the contact name on the SIM card (usually up to 15-20 characters) and do not support saving photos or additional numbers. Therefore, the system strongly recommends copying data to the phone memory or the cloud.
| Storage type | Contacts limit | Name length | Photo support |
|---|---|---|---|
| SIM card | 250-500 pcs. | ~15 characters | No |
| Phone memory | Unlimited | Up to 100+ characters | Yes |
| Google Account | Unlimited | Unlimited | Yes |
| USIM (4G/5G) | Up to 1000 pcs. | Up to 40 characters | No |
Transferring contacts from a SIM card to the Google cloud is the best way to protect your phone book from loss when changing a device or breaking a SIM card.
Access problems and SIM blocking
Sometimes the user cannot enter the SIM card menu due to software failures or physical blocking. The most common situation is a request PUK code after entering the PIN incorrectly three times. In this mode, access to most of the device’s functions is limited, and the phone only works in emergency call mode.
If the SIM card is displayed as “Unknown” or “No service,” the problem may lie in the oxidation of the contacts of the chip or slot itself. Try removing the tray, cleaning the contacts of the SIM card with a soft eraser and inserting it back, making sure that it lies flat.
In rare cases, a software glitch causes the communication module to freeze. Entering the settings menu becomes impossible, since the system does not see the hardware. The solution may be to reboot in safe mode or reset the network settings.
☑️ Diagnosing problems with SIM
Specifics of dual-SIM smartphones
Owners of devices with support for two physical SIM cards or one physical and one eSIM are faced with a complicated menu structure. The system Android allows you to flexibly configure usage scenarios, but the menu of each card is entered separately.
When you try to change settings, for example, enable roaming, the system will always clarify which SIM card the action is applied to. This protects against accidental expenses, but requires the user to be careful. In some shells, you can assign names to slots (for example, “Work” and “Personal”), which simplifies navigation.
Particular attention should be paid to the mobile data settings. In most cases, the Internet works only through one selected SIM card, while the second is only available for calls and SMS. Switching between them is fast, but may cause a short-term connection break.
⚠️ Attention: When using two SIM cards in 4G/5G mode, the second card often automatically switches to 2G/3G mode to wait for calls. This is normal behavior of DSDS technology (Dual SIM Dual Standby), and not a malfunction.
Frequently asked questions (FAQ)
How to unlock a SIM card if I forgot the PIN code?
If you have forgotten the PIN code, do not try to guess it endlessly. After three unsuccessful attempts, the phone will request a PUK code. It can be found on the plastic card to which the SIM card was attached upon purchase, or in the personal account of the mobile operator. Entering the wrong PUK code 10 times will lead to irreversible blocking of the SIM card, and then you will have to buy a new one.
Why does the code ##4636## not open the menu on my phone?
Smartphone manufacturers often block access to the engineering menu in stable firmware versions so that users do not accidentally reset the settings networks. This is especially true for the brands Xiaomi, Huawei and Honor. To access, you can try using third-party applications from the Play Market, such as “Force LTE Only,” which creates a shortcut to this menu, or use a computer and USB debugging (ADB).
Is it possible to find out your phone number through the SIM card menu?
Yes, often the phone number is stored in the SIM card profile. You can go there through Settings → About phone → SIM card status. However, if the number was not recorded by the operator when the card was issued (which is often the case), this field will display “Unknown”. In this case, the easiest way is to call another phone or dial the operator's USSD command (for example, *111# for MTS or *102# for MegaFon).
Safe Is it possible to change the network mode to “LTE Only”?
This is safe for the phone’s hardware, but can create communication problems. Voice calls on 4G networks are made via VoLTE technology. If your carrier or phone does not support VoLTE in your region, you will not be able to make or receive calls when you switch to LTE Only mode. Use this mode only if you are sure of VoLTE support or use your phone only for the Internet.
How to transfer contacts from one SIM card to another?
Direct transfer “card to card” without the participation of the phone is impossible. The algorithm of actions is as follows: insert the first card, copy contacts to the phone memory or Google account. Then remove the first card, insert the second and export contacts from the phone memory to a new SIM card through the contact management menu.