The situation when the screen of Xiaomi smartphone continues to burn during a conversation, familiar to many users. at best, it leads to accidental tapping of the cheek, at worst, to battery discharge and overheating of the device in the pocket. However, most often the reverse problem occurs: the display goes out too early, not allowing you to use the speakerphone or switch the subscriber.
The root of the problem lies in the proximity sensor, which is physically located at the top of the case. On Redmi and Poco smartphones, this sensor is often hidden under the screen or in a narrow frame, making it sensitive to contamination, protective films and even software failures of the MIUI or HyperOS system. Proper calibration and configuration of the software allows you to completely eliminate these inconveniences.
In this article, we will discuss in detail how to configure the screen to turn off when calling using standard system tools and hidden engineering menus. You will learn why calibration through the CIT engineering menu is the most effective method of solving sensor problems, and how to eliminate software conflicts that interfere with the correct operation of the smartphone.
The principle of the proximity sensor on Xiaomi smartphones
The automatic display shutdown is based on data from an infrared sensor. When you hold your phone to your ear, the sensor detects the change in reflected IR radiation and sends a signal to the system to lock the screen. Today's Xiaomi models use both a hardware and a virtual sensor based on machine learning algorithms.
The virtual proximity sensor analyzes the position of the phone in space using an accelerometer and a gyroscope. If the system "understands" that the device is near the ear, it blocks the touchscreen. However, software algorithms sometimes fail, especially if heavy applications are running in the background or if the case covers the upper edge of the case.
It is worth noting that some models with AMOLED screens use subscreen sensor technology, in such cases it is critical that there are no factory defects in the screen or poor-quality replacement of the display module, since the glue layer or the screen itself can distort the sensor readings.
- 📱 Hardware sensor: a physical element that responds to infrared rays located at the top of the front panel.
- 🤖 Virtual sensor: software algorithm that determines a use case based on accelerometer data.
- ⚙️ System handler: an OS component that makes a decision to lock the screen based on a data set.
Basic phone settings and checking for updates
Before you go to complex manipulations, you need to make sure that the basic system settings are correct. Often the problem is solved by a simple software update, as Xiaomi engineers regularly release patches that improve the performance of sensors. Go to the Settings menu → About the phone and check for new versions of MIUI.
It's also worth checking the settings of the Phone app itself. Google's caller or standard MIUI shell can have its limitations. Open the call app, click on three dots or a gear of settings, and find Incoming Calls. There shouldn't be active features here that prevent screen rotation or locking if they conflict with the sensor.
It is important to make sure that the phone does not activate In-pocket mode in the wrong mode. This feature is designed to prevent accidental pressing, but if it crashes, it can lock the screen at the wrong time. Turn it off for check: go to Settings → Lock and Protection → Mode in your pocket and turn off the switch.
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If you use a third-party “caller” (like Truecaller or Yandex), try temporarily returning to the standard Phone app. Third-party applications often do not have full access rights to the proximity sensor.
Sometimes it helps to simply reset your network settings, which restarts the radio modules and the services associated with them. It won't delete your contacts or photos, but will return the communication settings to factory values. The way to this feature is: Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.
Calibration of the sensor through the CIT engineering menu
The most effective way to fix a sensor’s software failure is to recalibrate it through the hidden CIT (Customer Integration Test) menu, which is built into the firmware of all Xiaomi smartphones and allows you to test and reconfigure hardware components without superuser rights.
To enter the menu, dial the universal code ##6484## in the call app. If the code didn't work, try ##4636## or find the Service and Feedback app (or simply the Service) in the list of all programs, then click repeatedly (about 10 times) on the application version icon in the top corner.
☑️ Checklist before calibration
In the test list, look for the Proximity sensor. Click on it. You'll see two values: Raw Data and current status. Palm the top of the screen (where the speaker is located) and remove it. Values should change from 0.0 to 5.0 (or vice versa, depending on the test version). If there is a reaction, but the screen does not go out when you call, press Calibration or Pass, following the instructions on the screen.
⚠️ Attention: Do not always cover the sensor during calibration, the system should record two states: "nothing is present" and "object is nearby." If after calibration the problem persists, try repeating the procedure. 2-3 Turning off the screen completely every time you try.
After a successful calibration, be sure to restart the device. The first call after a reboot can take longer to establish a connection, as the system re-interviews all sensors. This is normal behavior for Android smartphones after deep configuration changes.
Diagnostics with hidden codes and ADB
If the engineering menu is unavailable or malfunctioning, you can use more advanced diagnostic methods. For advanced users, you can enter commands via a computer using the ADB (Android Debug Bridge) toolkit, which allows you to get accurate data on the state of the sensor in real time.
To start, you need to enable USB debugging. Go to Settings → About Phone and click 7 times on MIUI Version until you have become a developer. Then activate USB Debugging from the Advanced Settings menu.
Connect the phone to your computer and enter a command into the console to check the status of the sensor:
adb shell dumpsys sensorIn the output, look for lines that contain proximity. You'll see current readings in microns or units. If you hold your hand to the screen, the values don't change, the problem may be hardware. If the values change, but the screen is on, the system ignores the sensor signal because of a software conflict.
| Method of diagnosis | Difficulty | Efficiency | Risk of failure |
|---|---|---|---|
| Reboot. | Low. | 30% | 0% |
| CIT menu | Medium | 85% | 5% |
| ADB Teams | Tall. | 95% | 10% |
| Resetting settings | Tall. | 90% | 20% |
What if the ADB can’t see the phone?
Effects of accessories and physical factors
Often, the cause of malfunction is a banal physical obstacle: protective glass with a wide black frame, thick covers or just contamination in the area of the speaker can block the IR rays, the sensor “thinks” that the phone is constantly in the ear, and keeps the screen off, or vice versa – does not see the approach.
Special attention should be paid to protective films. Cheap hydrogel films can have an uneven structure that distorts light. Try gently wipe the top of the screen with an alcohol wipe (carefully without pouring the speaker) or temporarily remove the protective glass to test the hypothesis.
When you get hot, like when you charge or play before a call, the sensors can work with errors, and let the device cool down before an important conversation if you notice such a dependence.
- 🧼 Cleanliness: Regularly wipe the top frame and speaker area with a soft cloth.
- 🛡️ Accessories: Use cases with accurate cutouts under sensors, avoid "deaf" frames.
- 🌡️ Temperature: Avoid calls at extremely low or high device temperatures.
⚠️ Warning: Do not use aggressive chemistry or abrasives to clean the sensor area.This can damage the oleophobic screen covering or the touch layer itself, leading to "dead zones».
Solving problems with third-party applications and resetting
If the software settings and calibration didn't help, the culprit could be a conflicting application. Often problems are caused by memory cleaners, antiviruses or call recording apps that intercept screen control. Try running your phone in Safe Mode.
To enter Safe Mode, press the off button, then press and hold the "off" button on the screen until a suggestion appears to go to Safe Mode. If the sensor is working correctly in this mode, delete the newly installed applications one by one, checking the result.
In the extreme case, when nothing works, there is a complete reset to factory settings.This action will delete all data from the phone, so be sure to back up your contacts, photos and documents to the Mi Cloud cloud or computer before starting the procedure.
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Wipe Data eliminates 99% of sensor software errors, but takes time to recover data, a last resort before you go to the service.
Reset is done via the Recovery Recovery menu. Turn off the phone, then press the power and volume buttons at the same time. In the menu that appears, select a language, then Wipe Data → Wipe All Data. Once you reboot, the phone will be as new, and the sensor problem will likely disappear.