When a Xiaomi smartphone screen suddenly lights up during an important phone call, and your cheek or ear activates unnecessary functions, many users are familiar with the situation. Instead of talking quietly, you have to look for a phone on the table to complete a call or, worse, accidentally send a voice message to a work chat. This problem is often associated with the incorrect operation of the proximity sensor, which stops blocking the display when you bring the device to your face.
The reason is software failures of MIUI or protective films that close the sensitive sensor, and in some cases, the design of the smartphone itself, where the sensor is not located well, is to blame, but most often it is enough to perform a few simple adjustments or calibrate to forget about random pressing forever.
In this article, we will look at all the possible solutions to the problem, from standard settings to the use of engineering menus, how to adjust the sensitivity correctly and why it happens on devices of the Chinese brand. It is important to understand that ignoring this error can lead to loss of important data or embarrassing situations.
Causes of false screen positives
The main culprit is the proximity sensor, which is a small sensor that sits at the top of the display, usually next to a speaker, and it's designed to determine the distance to the object (your ear) and turn off the screen to prevent accidental touch, and when that mechanism fails, the screen stays active.
Often, the problem arises after an update to the Android operating system or the MIUI shell. Developers can change the algorithms of the sensors, which leads to conflicts in the software. Also worth mentioning is physical pollution: dust, fat or glue residue from the protective glass can block the sensor, making it think that the phone is still in the ear, or vice versa – not see obstacles.
Another reason is cheap, black-framed security glass, and if the opaque part of the glass covers the area of the sensor, it can't physically read the distance, and in such cases, no software settings will help until you replace the screen protection with a better one or a model with a sensor cutout.
Standard interface settings
The first thing to do is check the basic system settings. In modern versions of Xiaomi firmware, sensor management is often hidden in the call menu. You need to open the standard Phone app and click on the three dots in the upper right corner to enter the settings.
In the list that opens, look for Incoming Calls or Call Settings. There should be a proximity sensor switch. If it's on, try turning it off and activating it again. This action restarts the distance monitoring service. In some versions of MIUI, this item may be called "Call Lock Screen."
If the switch is missing or not working, the problem may be deeper. Some users note that resetting the phone app itself helps. Go to Settings → Apps → All Apps → Phone. You can select “Clean” and click “Clean All.” Don’t worry, contacts and call history won’t be deleted, only the program’s settings will be reset.
☑️ Checking basic settings
Engineering menu and sensor calibration
If standard methods fail, you'll have to use a hidden engineering menu, which is a powerful tool for diagnosing and calibrating your smartphone's hardware, and be careful when you enter data, because changing other parameters can cause the device to malfunction.
Open the Phone app and dial ##6484##. The CIT menu will appear on the screen, and here is a complete list of tests for all components of the smartphone. You need to find the Proximity sensor on the list, usually at the top of the list or in the Common section.
Once you're in the sensor menu, you'll see two values: Distance and Raw data. Put your phone on a flat surface away from objects. Distance should be 5.0 cm (or close/far depending on the version). Put your palm to the top of the screen, the value should change by 0.0 cm. If the values don't change or jump, calibration is required.
What if the code doesn't work?
To calibrate the test menu, there is often a button called "Calibration" on the menu. Press it and follow the instructions on the screen: usually you need to close the sensor with your hand, then remove your hand and press "Pass" or "OK." After successful calibration, be sure to restart the smartphone with the Reboot command or simply turn off and turn on the power.
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Calibration through the engineering menu eliminates the software failure of reading data from the sensor, returning it to factory accuracy.
Use of third-party applications
When Xiaomi’s built-in tools are powerless, third-party apps come to the rescue, allowing more flexibility in controlling sensor sensitivity or even emulating it with software methods. One of the most popular solutions is the Proximity Sensor Reset/Fix app.
Once installed and given the necessary permissions, the app will conduct its own sensor test, and if any deviations are found, the program will suggest recalibrating, which is especially true for older models, such as the Redmi Note series or the entry-level Mi, where the sensors “float” over time.
Another option is to use call management applications that have their own lock-in system, ignoring the system sensor, and they use an accelerometer to determine the position of the phone in the ear, which is less accurate, but often more efficient than a broken-down standard sensor.
⚠️ Note: By installing third-party apps to work with system sensors, you give them broad access rights. Use only proven high-ranking programs on Google Play to avoid personal data leakage.
Influence of accessories and covers
Physical factors are not to be discounted. Very often, people buy beautiful covers or protective glass without thinking about compatibility with the design of their smartphone. If you notice a problem right after changing the glass, it's 99% of the reason.
Cheap security windows often have a solid black perimeter bezel, which is a frame that overlays the sensor that's under the glass, and as a result, the sensor "sees" the black bezel all the time and thinks that the phone is brought to the face all the time, or vice versa, it doesn't see anything because of the glue layer.
Also, magnetic rings for attachment in a car (PopSocket or magnets in a case) can create a problem. The magnetic field can (interfer) the work of Hall sensors or other magnetic sensors, affecting the overall stability of the positioning system.
| Accessory type | Probability of problem | Decision |
|---|---|---|
| Frameless protective glass | Tall. | Replacement with glass without frame or with a cutout |
| Hydrogel film | Low. | Bubble check in the sensor area |
| Thick silicone case | Medium | Cutting the cover in the speaker zone |
| Magnetic ring | Medium | Shifting the ring below the sensor |
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Try temporarily removing the cover and rubbing the top of the screen with an alcohol napkin, and if the problem is gone, it was an accessory or contamination.
Radical methods and discharge
If neither calibration nor replacement of the glass helped, there may have been a critical failure in the system files, in which case a full reset to the factory settings (Hard Reset) can help. Before you do this, be sure to back up all the important data to the Mi Cloud cloud or to your computer.
To perform the reset, go to Settings → About Phone → Settings Reset → Erase all data. This process will delete all apps, photos and contacts, returning the phone to the “out of the box” state. Often this eliminates deep software bugs accumulated over the years of use.
In extreme cases, even when the reset doesn't work, it can be a physical failure of the sensor plume or the sensor itself, and the proximity sensor is a separate module that could move away from the board when it falls, and only a call to the service center to replace the component will help.
⚠️ Warning: Complete data reset is irreversible.Make sure you remember the password from your Mi Account and Google account, otherwise the phone may be locked after the reset due to theft protection.