Users of smartphones based Android often face the need to fine-tune the network connection, which is not available through the standard settings interface. The usual menu offered by the manufacturer is usually hidden under layers of graphical shells and is simplified for the average consumer, leaving behind many technical parameters. If you are looking for a way to force switch your phone to 4G, check the signal level in decibels, or reset the modem settings, you need to get into the so-called SIM menu or engineering menu.
Access to these functions is not always obvious, since manufacturers deliberately limit direct access to them to avoid accidental breakdown communications. However, there are proven login methods that work on most devices from Samsung to Xiaomi. In this article, we will analyze all the legal ways to detect hidden sections for managing a SIM card and radio module.
It should be understood that the term “SIM menu” can be interpreted in two ways: this is either a classic menu of operator services (balance, tariffs), or, more likely in the context of configuration, a hidden engineering menu of the radio module. We will focus on the second option, since it gives real control over the quality of communication and the operation of network interfaces.
Classic menu of SIM card services through settings
The simplest and safest level of interaction with a SIM card is built right into the system. Here you will not find settings for frequencies or transmitter power, but you can manage basic operator services. To get there, you need to open the application Settings and go to the section Connections or Network and Internet.
Depending on the version Android and shell, the path may differ slightly. Usually you need to select item SIM card manager or Mobile network. This is where the settings for roaming, operator selection and PIN codes are stored. This is a “top-level” menu that does not require special codes for access.
If you need to call up the service menu of a specific operator (for example, “MTS Menu” or “Beeline Menu”), which is displayed as a list of items on the screen, a different mechanism is used. The system sends a USSD request of a special format, which forces the phone to display an interactive list.
- 📱 Go to
Settings → Connections → Mobile networks → Network operators. - 🔒 To change the PIN code, use the section
SIM card lockin the security settings. - 🌐 To enable data roaming, find the switch in the menu
Mobile networks. - ⚙️ Contacts on the SIM are managed through the standard application
Contact.
Engineering menu and secret access codes
The real “SIM menu” for advanced users is hidden behind special USSD codes that activate the engineering mode. Entering these combinations in a standard dialer provides access to diagnostics of the radio module. The most famous and universal code for devices on chips MediaTek and many others is ##4636##.
After entering the last asterisk, the menu should open automatically. You will see a section Phone informationwhere the current network settings, connection type and signal strength are displayed. There is also a drop-down list Preferred network typethat allows you to rigidly fix the operating mode, for example, only LTE Only.
For smartphone owners Samsung there is a unique code - *#0011#. It opens the service menu with detailed information about the network status in real time. Here you can see not only the signal level, but also the number of the base station to which the device is connected, as well as the channel bandwidth.
⚠️ Attention: Some codes may be blocked by the telecom operator or firmware manufacturer. If the code does not work, try installing a dealer application (for example, QuickShortcutMaker) to find hidden system activities.
Be careful when changing parameters in the engineering menu. Incorrect configuration can lead to a complete loss of communication, which sometimes cannot be corrected without flashing the device. Always remember the original values before changing them.
Setting network priority and operating modes
One of the main reasons for searching for a hidden SIM menu is the need to force a switch to 4G or 5G in areas with unstable coverage. Standard settings often allow the phone to “sink” to 3G or even 2G to save energy, which critically reduces Internet speed.
In the menu ##4636## you can select the mode LTE Only. This will cause the modem to ignore all other network types. However, this solution has a downside: in most cases, with this mode voice calls will become unavailable if your operator does not support VoLTE technology.
A safer option is to select the mode LTE/TD-SCDMA/WCDMA or a similar combined option, where 4G comes first. This gives priority to high-speed Internet, but allows the phone to switch to 3G for making calls if LTE coverage drops.
Path to setup:1. Enter ##4636##
2. Select "Phone Information"
3. Find "Set preferred network type"
4. Select the desired mode from the list
If the connection is lost after changing the mode, try turning “Airplane Mode” on and off. This will forcefully restart the radio module and force it to re-register with the network with new parameters. In some cases, a complete reboot of the device is required.
☑️ Checking the network mode
Diagnostics of signal and information about the base station
For those who are installing external antennas or simply want to understand why the connection is bad, information about the signal level is critically important. In the normal interface we see only “sticks” that do not give an accurate idea of the quality of the connection. The engineering menu provides data in numerical format.
The key parameter is RSRP (Reference Signal Received Power) for 4G networks. The value is measured in dBm and typically ranges from -50 to -140. The closer the value is to zero (for example -80), the better the signal. Values below -110 are considered extremely weak.
It is also worth paying attention to the parameter SINR (Signal-to-Interference-plus-Noise Ratio). It shows the ratio of useful signal to noise. Positive SINR values indicate a clean signal, while negative values indicate strong interference, even if the signal strength (RSRP) itself is high.
| Parameter | Description | Good value | Bad value |
|---|---|---|---|
| RSRP | Signal power level | -80 dBm and above | Below -110 dBm |
| SINR | Signal-to-noise ratio | More than 20 dB | Less than 0 dB |
| RSSI | Total signal strength | -70 dBm | Below -100 dBm |
| TAC | Tracking area code | Any number | 0 (error) |
Knowing these parameters, you can optimally place the router or antenna in the house, focusing not on “sticks”, but on real numbers. Moving the device even half a meter can significantly change the SINR.
What is Cell ID?
Cell ID (CID) is a unique identifier of the cell (base station) to which your phone is connected. Knowing the CID, you can determine the geographic location of the tower through specialized online services, which is useful for setting up directional antennas.
Resetting network settings and re-registering SIM
Sometimes communication problems are caused not by poor coverage, but by a software failure in registering the SIM card in the operator’s network. The phone may become stuck on an old tower or the profile settings may not be updated correctly. In such cases, a forced reset of the network settings through the engineering menu helps.
The Phone information section often contains buttons Run Ping test or Update SMSC configuration. Clicking the SMSC (message center) refresh button may resolve SMS sending issues. Resetting network preferences is also useful.
A more radical, but effective method is to completely reset the network settings through the system menu. This will remove saved APNs, Wi-Fi passwords, and Bluetooth settings, but will return the radio to its factory state. To do this, go to Settings → System → Reset settings → Reset Wi-Fi, mobile data and Bluetooth settings.
⚠️ Attention: Before resetting your network settings, be sure to write down your current access points (APNs) if your operator requires you to manually configure them. After the reset, the Internet may not work until you enter this data again.
If standard methods do not help, you can try removing the SIM card, wipe the contacts with a soft eraser and insert it back. Physical contact plays a huge role in the stability of the module.
If your phone often loses the network, try manually selecting an operator in the "Search for networks" menu, and then return to the "Auto selection" mode. This will update the list of available towers in the modem cache.
Manufacturer restrictions and firmware features
It should be taken into account that smartphone manufacturers are constantly making it more difficult to access hidden functions. In the latest versions Android (11, 12, 13 and later), many engineering codes have been disabled at the system level for security reasons. The code may simply not open the menu on new ones. They use legal API systems to obtain the same information as the engineering menu, but in a more convenient and understandable form. These applications can even build coverage maps based on your data. ##4636## it may simply not open the menu on new ones Google Pixel or Samsung.
In such situations, third-party applications from Google Play, such as NetMonster or CellMapper. They use legal API systems to obtain the same information as the engineering menu, but in a more convenient and understandable form. These apps can even build coverage maps based on your data.
For devices Xiaomi with a shell MIUI there is a separate engineering menu called by code ##6484##. It contains tests not only of communication, but also of all sensors, screen and sound. Section CIT (Customer Integration Test) allows you to conduct in-depth hardware diagnostics.
Without superuser rights, you will not be able to change certain system files responsible for the configuration of the radio frequency path. However, for most tasks for setting up the SIM menu, root is not required.
If standard codes do not work, use network analyzer applications from Google Play - they provide the same data in a legal way without the risk of breaking the system.
Frequently asked questions (FAQ)
Is it safe to change the network mode to LTE Only?
This is safe for the phone, but may prevent you from making regular voice calls if your carrier does not support VoLTE. In case of emergency, you will not be able to call the emergency services. Use this mode only for working with the Internet.
Why does the code ##4636## not work on my phone?
The manufacturer of your firmware may have disabled this code. Try entering it slowly, letter by letter. If this does not help, install the application QuickShortcutMaker, search for "Testing" or "Phone Information" and create a shortcut for the hidden menu.
Is it possible to increase the transmitter power through the SIM menu?
In most civilian firmware, this function is blocked. Changing the transmitter power is only available in service menus available to authorized centers, or requires deep intervention in the system, which can lead to damage to the radio module.
How can I find out if my phone supports 5G through the engineering menu?
In the list of preferred network types, look for items marked NR (New Radio). If there are such items (for example, NR/LTE/TD-SCDMA/GSM), then the modem hardware supports 5G. The absence of such items indicates that the phone does not have a 5G module.
What to do if the Internet is lost after the settings?
Return to the engineering menu and select the mode NR/LTE/GSM/WCDMA (Auto connect) or a similar one marked Auto. Then restart your phone. If this does not help, perform a complete reset of the network settings in the system menu.