Brand smartphones Xiaomi, including sub-brands Redmi i Poco, are famous for their price-quality ratio, but users often encounter incorrect operation of touch components. One of the most common and annoying problems is the malfunction of the proximity sensor, which is responsible for turning off the screen during a call. If the screen doesn't turn off when you hold the phone to your ear, you run the risk of accidentally pressing the call reset button or activating the speakerphone with your cheek. In some cases, the screen, on the contrary, does not turn on after the end of the call, forcing the user to restart the device.
Before taking the device to a service center, it is necessary to conduct self-diagnosis to understand the nature of the malfunction. This could be a software failure, sensor contamination, or physical damage to the module. In this article we will analyze in detail all available verification methods proximity sensor, from built-in engineering tests to third-party utilities. Understanding how this component works will help you quickly identify the problem and choose the right way to solve it.
It is worth noting that the architecture of the sensor location changed from model to model. In old devices it was located in the top frame, in new ones it was often integrated into the front camera module or even under the display. Therefore, diagnostic methods may vary slightly depending on the specific model of your Androidsmartphone. We will consider universal methods suitable for most current versions of the shell MIUI and HyperOS.
The principle of operation and types of sensors in the Xiaomi ecosystem
The proximity sensor is a small module consisting of an infrared LED and a photodetector. The principle of its operation is based on the emission of light invisible to the eye and analysis of the reflected signal. When you hold the phone to your head, the beam reflects off the skin of your ear and returns to the receiver, sending a signal to the system to lock the display. In modern models Xiaomi this process is optimized to save energy and increase accuracy.
There are several types of implementation of this technology. The classic discrete sensor is a separate window next to the earpiece. More advanced solutions use a virtual sensor, the data for which comes from the accelerometer and gyroscope, or an infrared module combined with the front camera. Understanding your device type is important because software calibration methods work differently for each device. Errors in operation often arise precisely because of incorrect interpretation of data by these complex systems.
⚠️ Attention: On some models with a frameless design, a physical sensor may be absent as such; its function is performed by an algorithm based on data from other sensors. In such cases, standard engineering menu tests may show incorrect results or be absent altogether.
Incorrect operation infrared emitter can be caused not only by breakdown, but also by simple contamination. Dust, finger grease, or remnants of a protective film covering the top of the screen can distort the signal. The system receives false information that an object is in close proximity and blocks the screen at the wrong time. Regular cleaning of the top edge of the device is the simplest measure to prevent such failures.
Use a microfiber cloth to wipe the top of the screen and the area around the front camera. Avoid using aggressive chemicals that can damage the oleophobic coating.
Diagnostics through the CIT engineering menu
The most reliable and fastest way to check the performance of hardware components is to use the built-in engineering menu CIT (Country Information Test). This hidden section of the system provides access to tests of all sensors, including the accelerometer, gyroscope and, of course, the proximity sensor. To enter the menu, you will need to enter a special code in the Phone application. This method does not require the installation of third-party software and works at the firmware level.
To start the test, open the calling application and dial the combination ##6484##. If the code is entered correctly, you will automatically be taken to the testing menu. In the list, find the item Proximity sensor (Proximity sensor) and click on it. A screen will open in front of you with numerical values that change in real time. Typically, two parameters are displayed there: distance in centimeters and status (Near/Far).
Wave your hand in front of the top of the smartphone without touching the screen. If the sensor is working properly, the values on the screen should change instantly. The status will switch from Far (far) to Near (close), and the digital distance value will decrease. If the numbers stand still or change chaotically without moving your hand, this is a direct sign of a hardware malfunction or a serious driver software failure. In this case, a simple reboot may not help.
☑️ Checking in the CIT menu
Sometimes the CIT menu displays "0" or a constant "Near" even when there is nothing in front of the phone. This may indicate that the sensor is stuck closed. Try gently tapping the top of the case or applying light pressure to the sensor area. If the values begin to change, the problem may be poor contact of the cable inside the case. However, if there is no reaction at all, most likely the module has failed and requires replacement.
Using third-party applications for testing
If for some reason the built-in engineering menu is inaccessible, blocked by the operator or produces an error, specialized applications from the store will come to the rescue. Google Play. There are many utilities developed by enthusiasts that read data from sensors directly via Android API. Such apps often provide more visual graphics and the ability to record logs for sending to developers.
One of the popular solutions is the application Sensor Test or Phone Doctor Plus. After installation, run the app and select the section with the proximity sensor test. The interface usually simulates a lock screen or shows a graph of values. Place your finger on the top of the body and watch the reaction. The advantage of such applications is that they can show the history of values, which is useful for identifying intermittent problems (when the sensor works every once in a while).
- 📱 Sensor Test - a simple application that displays raw data from all sensors of the device in real time.
- 🔧 Phone Doctor Plus - a comprehensive diagnostic tool that not only tests, but also gives recommendations for troubleshooting.
- 📊 AIDA64 —a powerful utility for obtaining detailed technical information about a smartphone, including detailed reports on sensors.
If the application shows that the sensor is working, but the problem during calls persists, then the conflict arises at the level of the call processing system or third-party applications that intercept control of the screen. In this case, it is worth checking the permissions of installed apps.
Why can applications lie?
Some applications cache sensor data to save battery, so readings may be updated with a delay of 1-2 seconds. For accurate diagnostics, it is better to use real-time mode or the engineering menu.
Sensor calibration through system settings and codes
Some versions of the shell MIUI provide the ability to software calibrate the sensor. This procedure is necessary if the sensor is physically functional, but does not correctly determine the response threshold. For example, it may fire too early or too late. Calibration resets the reference distance values stored in the controller's memory.
To start calibration, the same entry to the engineering menu is often used via code ##6484##. Select item Proximity sensor. The test screen may display a "Calibrate" button or instructions to place the phone on a flat surface and cover the sensor. Follow the instructions on the screen: usually you first need to close the sensor (put the phone face down on a table or cover it with your palm), wait for confirmation, and then open it. After successful completion of the procedure, the message "Calibration Success" will appear.
| Device model | Calibration method | Sensor location | Frequent problems |
|---|---|---|---|
| Redmi Note 8/9 | CIT engineering menu | Top frame | Dirty, software failure |
| Xiaomi Mi 11 | Automatic when loading | Under the screen | Incorrect operation in bright light |
| Poco X3 Pro | Manual via CIT | In the camera module | Removing the cable |
| Redmi 10 | Resetting settings | Top frame | The influence of protective glass |
If standard calibration does not help, you can try a more radical method through the recovery menu or special reset codes. Enter the code ##64663## (if supported by your firmware version) to access advanced testing. Sometimes completely resetting your phone helps, but this is a last resort and requires first saving the data. Remember that calibration will not fix a physically broken module.
Successful calibration is confirmed by a system message. If after the procedure the problem persists, a hardware malfunction is likely.
The influence of accessories and external factors on the operation of the sensor
Often the reason for the incorrect operation of the proximity sensor lies not in the smartphone itself, but in the accessories used. Low quality screen protectors and films may have an opaque edge or simply be too thick at the top, blocking the infrared ray. Even a microscopic displacement of the glass by half a millimeter can completely block the operation of the sensor.
Try to temporarily remove the protective glass and test the phone's operation in talk mode. If the problem disappears, then the problem is with the accessory. In this case, it is recommended to replace the glass with a thinner one or a model with a cutout for the sensor (the so-called “glass with an eye”). It is also worth checking the case: some massive bumpers can cover the upper edge of the case, interfering with the normal operation of the optics.
⚠️ Attention: Cheap protective glasses with a black frame around the perimeter often block the proximity sensor on Xiaomi smartphones. When purchasing, make sure that there is a transparent cutout or indentation at the top of the glass.
In addition to accessories, external conditions affect the operation of the sensor. Bright, direct sunlight contains a lot of infrared radiation, which can blind the smartphone's receiver. Under such conditions, the sensor may behave unpredictably. Also, the presence of foreign objects in the case, for example, magnetic fasteners, can interfere with the operation of magnetic sensors, indirectly affecting the logic of the screen lock system.
Software conflicts and factory reset
If the hardware and accessories are in order, it is worth looking for the reason in the software. Conflicting applications, especially those that control calls, screen locks, or have rights to change system settings, can intercept sensor signals. Consider whether you recently installed new apps before the problem appeared. Try booting your smartphone into Safe Modeto disable all third-party applications.
To enter safe mode, hold down the power button, and then long-press the “Shut Down” (or “Reboot”) option on the screen until you are prompted to switch to safe mode. If the sensor works correctly in this mode, it means that one of the installed applications is to blame. Remove them one by one and check the results. Pay special attention to "cleaners", antiviruses and launchers.
As a last resort, when nothing helps, you can reset to factory settings. This will erase all data and return the phone to its original state. Before doing this, be sure to back up your contacts and photos. Go to Settings → About phone → Reset settings and select "Delete all data". Often, after a clean installation of the firmware without user debris, the sensor begins to work like new.
adb shell settings put system proximity_on_open 1For advanced users, it is possible to configure the behavior of the sensor via ADB (Android Debug Bridge). By connecting your phone to your computer and enabling USB debugging, you can enter a command to force certain sensor features on or off. However, using the command line requires caution: an incorrect parameter may cause system instability. Use this method only if you are confident in your actions.
Hardware repair and module replacement
When all software methods have been exhausted, and the sensor in the engineering menu shows zeros or does not respond to movements, only hardware repair remains. In most cases, the sensor module itself or the ribbon cable to which it is attached will need to be replaced. On modern smartphones, the sensor is often integrated into the front camera cable or into a separate small cable on the top of the case.
The replacement process varies depending on the model. On devices with a removable back cover, access may be easier, while on all-in-one PCs with an adhesive base, heating the case and using suction cups is required. If you do not have experience in repairing electronics, it is better to entrust this procedure to specialists. Unprofessional opening can lead to damage to the display or damage to the moisture protection of the device.
- 🛠️ Diagnostics with a multimeter —the technician will check the integrity of the power and signal circuits on the board.
- 🔌 Replacing the cable —the most common procedure, since the sensor rarely comes separately detail.
- 🧹 Cleaning contacts - sometimes clean oxidized contacts with alcohol to restore operation.
The cost of repairs is usually low, since the sensor itself is an inexpensive component. The main part of the price for the service is the work of disassembling and assembling the device. If the smartphone is under warranty and there are no signs of mechanical damage or moisture, repairs should be performed free of charge at an authorized center. Keep the receipt and warranty card for reference.
When ordering spare parts for self-repair, always indicate the exact model of the device. The cables from Redmi Note 8 and Note 8 Pro are visually similar, but may have different connector pinouts.
Why does the sensor not work only in messengers (WhatsApp, Telegram), but works in regular calls?
This is due to the fact that different applications use different APIs to access the sensor. The standard Phone application has system privileges, while instant messengers work in a limited mode. The problem may be in the energy saving settings for a specific application or in a bug in the app itself. Try updating the messenger or clearing its cache.
Is it possible to disable the proximity sensor programmatically if it is broken?
There is no direct switch in the Android settings, but there are deception applications (for example, "Proximity Sensor Fix") that emulate the operation of the sensor or forcefully keep the screen on during a call. You can also use gestures (for example, double-tapping to turn on the screen) to compensate for the lack of auto-wake.
Does flashing the phone affect the operation of the sensor?
Yes, installing custom firmware (Custom ROM) can both fix the problem (if there was a bug in the stock) and aggravate it (if the custom one does not have the correct ones) drivers for your hardware revision). Before flashing, be sure to study the developer forum (4PDA, XDA) for known problems with the sensor for your model.
What should you do if the screen goes out on its own in your pocket?
This is a sign of excessive sensitivity or false positives. Try using a case with a magnetic clasp (if your phone supports a magnetic holster sensor) or disable the "Remove from Pocket" feature in your lock settings. Also check if something is pressing on the screen inside the pocket.
Is it true that Xiaomi sensors often break?
Statistics show that this is not a massive defect, but rather a feature of the layout and sensitivity to external factors (dust, glass). The modules themselves are reliable, but their location in a narrow frame makes them vulnerable to contamination and shock when dropped.