How to turn on screen lock when calling on Xiaomi

Many Xiaomi, Redmi and POCO smartphone owners face an annoying problem: during a phone conversation, the screen goes out and then suddenly lights up again, which leads to accidental cheek tapping, resetting the call or turning on the hands-free connection without your knowledge, a situation often caused by the proximity sensor or the incorrect settings of the MIUI and HyperOS shell interface.

Turning on the screen locking correctly when talking is not just a matter of convenience, but also a necessity to save battery power. When the display is active during the time, the energy consumption increases significantly, and the risk of unlocking the device in your pocket becomes a real threat to the security of your data. In this article, we will discuss in detail how to adjust this setting and fix sensor failures.

Principle of operation of the proximity sensor and screen

The main thing that's going to quench the display during a conversation is the proximity sensor, and this little sensor that's on top of the smartphone's body emits infrared light and reads the reflection of the object, and when you hold the phone to your ear, the sensor picks up the change in distance and signals the system to turn off the touchscreen and the display.

But Xiaomi and Redmi often use what they call a virtual sensor, which, unlike its hardware counterpart, analyzes data from an accelerometer, a gyroscope, and a front camera to calculate the device's position in space, and it's the algorithms that process that data that sometimes fail to cause the screen to light up at the wrong time.

If the software lock doesn't work, it may be a physical barrier, poor quality protective glass or thick covers can block the sensor's range, causing the system to "think" that the phone is no longer in the ear, and turn the screen back on.

⚠️ Attention: Using cheap black-framed protective glasses often overrides the proximity sensor, making the screen lock function idle.

Basic lock settings in the call menu

The first step to fix the problem is to check the standard settings of the Phone application. In the MIUI shell, the call functionality is extended, and some options can be hidden or disabled by default after the system update. To access them, you need to open the Phone application and click on three dots in the upper right corner.

In the menu that opens, select Settings, then go to Incoming Calls, and there's a key switch that's often called "Pocket Mode" or "Push Lock," which activates it to make the system more responsive to sensor signals and force the screen to go out when you start a conversation.

Also in this section, you should pay attention to the option “Vibration on connection”, although it does not directly affect the screen, turning it off can reduce the load on the processor at the start, which indirectly helps to avoid interface lags, which may not cause the screen to go out in time.

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If the Mode in Your Pocket switch is already on, try turning it off, restarting the phone and turning it on again – this will reset the telephony service cache.

Calibration of the proximity sensor through the engineering menu

If the standard settings don't work, you need to calibrate the sensor, which is the most effective method for models with a virtual sensor. To enter the engineering menu, open the Phone app and type ##6484##. The CIT (Customer Information Test) menu will appear on the screen.

In the test list, look for the Proximity Sensor. Make sure the top of the phone is clean before you start the test. Press Calibration or Pass, following the instructions on the screen. Usually, the system will ask you to close the top of the phone with your hand and then open it.

Once the test is completed, the values should change from 5.0 to 0.0 (or vice versa depending on the software version). If the calibration is successful, be sure to restart the device to apply the new parameters.

Impact of Design Theme and System Failures

The MIUI shell is deeply integrated with the theme. Third-party themes downloaded from Themes store may contain errors in the screen blocker code. If the problem occurs after you install a new theme, try returning the standard "Classic" or "No Limits" design.

Often the reason that the screen does not go out is a crowded cache of the Phone application or the System UI system service. The accumulation of temporary files can lead to incorrect processing of signals from the sensors. Cache cleaning is performed through the application management menu in the settings.

In rare cases, conflicting applications that have access to lock screens or calls are disrupted, such as number detectors or third-party call recordings that can intercept the display. Try running the phone in safe mode to eliminate the impact of third-party software.

⚠️ Warning: Resetting all settings to factory will delete your data.Be sure to back up your contacts and photos in the Mi Cloud before doing so.

Comparison of sensor behavior on different models

Different generations of Xiaomi smartphones use different technologies to protect against random clicks. Flagship models are more often equipped with physical sensors that work more stable, while budget lines rely on software algorithms. Understanding the differences helps to choose the right method of solving the problem.

The table below compares sensor types and the typical problems of popular series of devices to help you understand whether your screen behavior is the norm for a given model or requires intervention.

As you can see from the table, the approach to the solution should be individual. For owners of Redmi Note with a virtual sensor, the most critical will be the software calibration, while owners of old flagships should simply wipe the case.

Additional methods of troubleshooting

If none of the above methods helped to enable a normal lock screen, it is worth considering more radical measures. Sometimes the problem lies in a specific firmware update that contains bugs. Check for system updates in the Settings → About phone menu.

There is also a hidden debugging feature available through ADB that allows you to force the sensor sensitivity to change, but using the command line requires caution. It is safer for the average user to perform a complete reset of network settings and calls.

As a last resort, if the screen continues to burn and drain the battery, you can install a third-party call management app from the official Google Play Store, which can take precedence over the system interface of the call and correctly block the touchscreen.

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If the screen goes out but immediately lights up again, the problem is 90% in software conflict or calibration, not hardware.

Frequently Asked Questions (FAQ)