Get more with your Smartphone as the manufacturer allowed – without rooting for. Special digits codes elicit additional information and features the mobile device. But beware: this is not without risk.
Normally, you control your Smartphone or Tablet menu of the operating system, or the apps. Achieve certain functions, but only through commands: digit combinations that you enter a phone number from the phone app of the mobile device are.
Many of these features are actually not designed for the users, but for the mobile operator or service technician: for this reason, very few are publicly documented.Therefore you should definitely trying it out be sure carefully: in most cases, the phone emits only an error message if it doesn’t know the command – for example, “connection problem or invalid MMI code”. But also, it can crash: then only a restart helps.Particularly nasty commands delete even the Smartphone.
Special commands for individual smartphones
There are control codes that are running directly on the device: here it is enough to enter the digits, something going on. The problem: Most of these secret codes only work on certain models, and often only if a specific Android version boils. For example, combining an advanced service menu opens *#0*# on the Samsung Galaxy. With which, you can test, for example, the colors of the screen to discover non-functioning pixels. Or check if vibration or location -, light -, and Acceleration sensors on the Smartphone work.A similar test mode, for example, the HTC desire X offers: Here you have the function via* #* #3424#*# * call.
Read unit number on the mobile device
A unique device number, the so-called IMEI international mobile station equipment identity has each cell and each tablet with built-in mobile phone hardware. Certainly, it is worth to know this number, because in the event of loss, you identify your phone easiest via the IMEI. This works even if someone in the meantime has to reset the device to factory settings. To know the number also helps in the lost property office, when there someone must convince you that the phone is yours.
Here’s how: the IMEI will appear when you start the phone app and enter this code: * #06#. You can transcribe the IMEI or simply to make a screen shot of the number, and then send it to the PC. Screenshots on your Smartphone succeed mostly through a keyboard shortcut, which you hold for some time. Examples are: on/off button with on/off button with home button or volume down button. Or hold the power button down for something and get a drop-down menu. At IOS Press on/off button with home button.
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Battery and system info on your Smartphone display
The code * #* # 4636 * you come in an extended Info menu. The point of “Arrow” displays the temperature of the battery and you will see the operating time of the device. See “Usage statistics” for info about that what apps since how long are active. And finally, there is information on the status of the wireless connection and the configuration of the associated access point under “WiFi Information”, for example, whether it uses DHCP and Wi-Fi connection is secured with what encryption. The code works without a SIM card inserted, because he directly speaks on the phone.
Android commands for the cell phone network
Enter a GSM or MMI code against it, the phone must have a connection to the mobile network. Because these commands the Smartphone sends a request to the mobile network operator to adjust network-internal functions. For example, you can prevent the display of your number for calls with #31#. Other GSM codes check the status of your phone for call forwarding with non-acceptance, availability or filled out.
Another example is the code of *#21#. It displays the current status of call forwarding. Launch the phone app and enter the code *#21#. The app displays the status of call forwarding. The following commands change the call forwarding: set up with * 21 *, delete with # 21 #, use #21# to disable and enable with * 21 #. Because these codes to the phone provider will be sent, depends on it from your provider, which commands it supports and which are not. GSM codes must be sent with the call button
Works similarly to the communication via USSD commands (unstructured supplementary service data): corresponding number codes are often used in prepaid phones to display about the account balance of the prepaid card. Most of the USSD codes go only at certain mobile radio providers: O2 customers, for example, can display with the numerical code *140# is the current invoice amount in their tariff.
Threat of Android code
Like the GSM codes, USSD commands are sent typically only when you press the call button in the phone app. However you can also automatically run – a USSD code and then it becomes dangerous: in conjunction with the command tel: a USSD code as a link on a Web page can be deposited. Then it can happen that the Smartphone automatically performs the control code when the browser opens the Web page. Such a code can be on the Web page deposit, which changes the PIN or reset the phone to factory settings.This problem was already publicly for the Samsung Galaxy S3. But even smart phones of other manufacturers such as HTC and LG are affected.
How to protect yourself from dangerous codes
For devices with jelly bean (Android 4.1), Google has fixed this vulnerability: no longer automatically executes the malicious code the phone app, you can cancel the operation so. Similar security apps such as NoTelURL work: This app prevents calls to phone numbers from the Web browser. You want to use this function, however, is advisable TelStop : The app prevents USSD code from running automatically. If you really want to run the call command, you can select the usual phone app for this.