Xiaomi smartphones are well-deservedly popular for their excellent value for money, but the MIUI software shell often presents users with unpleasant surprises. One of the most common and annoying problems faced by owners of the Redmi 9 model is the incorrect operation of the proximity sensor, which manifests itself in the fact that during a phone conversation the screen goes out prematurely or, conversely, does not turn off when you hold the phone to the ear, which causes random buttons to be pressed with the cheek or ear.
Many users are immediately looking for ways to disable the proximity sensor on the Xiaomi Redmi 9 to relieve the constant stress during calls. Fortunately, Android and the MIUI shell have mechanisms to solve this problem, although they are not always obvious at first glance. In this article, we will discuss in detail all the available methods, from simple settings in the menu to the use of engineering codes and third-party applications.
Now, you know, shutting down this sensor completely is a temporary solution that will help you communicate comfortably until you calibrate or repair it, and ignoring the problem can cause you to accidentally hang up your phone or turn on speakerphone at the most inopportune moment, and let's look at why this happens and how to take back control of your device.
The reason for the incorrect operation of the sensor on the Redmi 9
Before we go to radical measures and shut down the function, we need to understand the root of the problem. On the Redmi 9, the proximity sensor is often located at the top of the screen, and its operation can be interfered with by physical obstacles. The most common but common cause is a low-quality protective glass or improperly pasted film that covers the sensitive element.
The second reason is software failures in the MIUI operating system. After updating the firmware, the algorithms of the sensors can change, which leads to conflicts. System errors sometimes accumulate in the cache of applications responsible for phone calls, which requires cleaning the data or resetting. Software glitch can also be caused by third-party applications that access screen control.
⚠️ Note: If your screen is broken or the display has been replaced with a non-original module, the sensor may not work properly due to hardware incompatibility.
A third group of reasons is related to magnetic fields: cases with magnetic fasteners or carrying a phone near powerful radiation sources can disorient the sensor. Redmi 9 is equipped with a virtual proximity sensor that works on algorithms that analyze data from the gyroscope and accelerometer, making it more susceptible to program errors compared to physical counterparts.
Standard phone settings for sensor control
The standard MIUI interface doesn't have a single "Switch off the sensor" button, but there are settings that affect its behavior. The first thing you should do is check the lock and call screen settings. Go to the Settings menu, then select the "Screen Lock" section. Here you should find Mode in your pocket and turn it off. This feature uses the proximity sensor to detect where the phone is in your pocket, and its operation often conflicts with the logic of calls.
Then you go to the settings of the Phone app itself. Open the caller, click three dots in the corner of the screen and select Settings. Incoming calls or Additional settings (depending on the version of MIUI) may have an option called the Approximation Sensor. If you have one, just turn it to the Off position. This will prevent the system from extinguishing the screen during the call.
☑️ Checking standard settings
If the standard menu does not have a switch, which is often the case on global versions of firmware, you can try to change the settings through the special features menu. Go to Settings → Advanced Settings → Special. Here you need to find the tab corresponding to the Phone application (usually called Google Phone), and look for options related to the screen or sensors. Sometimes changing the theme to the standard one helps, since third-party themes may contain errors in screen control scripts.
Use of the Engineering Menu for Calibration and Disconnection
The most effective way to solve this problem is to log into the engineering menu, hidden from the average user. It's a powerful tool for diagnosing and configuring hardware components. To get there, open the Phone app and type in the code ##6484#. If the code fits, the CIT menu will open. If the code doesn't work, try #4636#, although it's more commonly used to set up the network.
You need to find Proximity Sensor in the CIT menu. You click on it and you'll see the current sensor readings. Close the top of the screen with your hand, the value should change from 5.0 to 0.0 (or vice versa, depending on the version). If the values don't change or change randomly, press Calibration. Follow the instructions on the screen: usually you need to remove your hand, press OK, then close the sensor and press OK again.
| Parameter | Meaning without impediment | Importance with the obstacle | Status |
|---|---|---|---|
| Distance (Distance) | 5.0 cm | 0.0 - 1.0 cm | Norma. |
| Raw Data | High. | Low. | Depends on the model. |
| State | Near (Close) | Far (far away) | Change. |
| Calibration | - | - | Required when a failure occurs |
If calibration doesn't work, some versions of the engineering menu (especially on older firmware or through special applications like Engineering Mode MTK) can find the option of forced disabling the sensor. However, on Redmi 9 with newer versions of Android, this feature is often hidden, in which case, after unsuccessful calibration attempts, it is better to immediately switch to using third-party software that can intercept sensor commands.
What to do if the engineering menu is not opened?
Application of third-party applications for control interception
When Xiaomi's built-in tools fail to solve a problem, Google Play apps come to the rescue, and they act like intercepting system events: the app "sees" that a call has started, and forcibly changes the screen settings, ignoring the sensor readings. One of the most popular and proven solutions is the Proximity Sensor Fix app or its counterparts, such as Lesser Screen Off.
Once you install an app, you'll need to give it the permissions you need, which are usually phone access, contacts, and most importantly, the right to overlay over other apps. Without that permission, the app won't be able to block screen suppression. In the app settings, you'll need to choose a "Fix during call" or similar profile, which will cause the system to ignore the sensor at the time of the connection.
⚠️ Note: Using third-party applications to manage system functions can lead to increased battery consumption.
There's also a way of using macros through MacroDroid or Tasker. It's a more complex, but flexible way. You can create a macro: "Trigger: Bell starts" → "Action: Screen on" or "Action: Brightness 100%." This approach allows you not to turn off the sensor completely, but simply to prevent the screen from dimming, which solves the problem of accidental cheek pressing, but retains functionality for other tasks.
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When installing locking applications, be sure to add them to the Battery Saver exclusion list, otherwise the MIUI system will force the process to close and the fix will stop working.
Resetting settings and cleaning the application data Phone
If software conflicts are caused by accumulated debris or misconfigurations, resetting the call component will help. This is a secure procedure that will not delete your contacts or call history, but will return the call settings to the factory settings. → Annexes → All applications.
In the list, find the Phone app (green tube icon). Click on it and select Memory. Here you press two buttons: Clear cache and Clear all (or Reset). After that, repeat the same steps for the Handbook (or Contacts) application, as they are closely related. After cleaning, be sure to restart the device so that the changes take effect.
In some cases, the problem lies in updates to Google's Phone app itself. If the problem has recently appeared, try removing updates to that app. Go to Settings → Apps → Phone (Google), click three dots in the corner and select Remove Updates. The system will roll back to the factory version of the call, which may be more stable for your version of MIUI.
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Cleaning up the phone application data and removing its updates often solves the problem of false sensor positives if it is caused by a software failure after a system update.
Hardware factors and physical interventions
You can't rule out a physical breakdown, too. If software methods, including calibration and resetting, haven't worked, maybe the sensor is damaged. On the Redmi 9, the proximity sensor is often combined with the top speaker. Moisture, dust, or impact can cause it to fail. Visually inspect the top of the phone for chips, cracks, or corrosion.
Sometimes it helps to clean the sensor area carefully, you can use a soft toothbrush or a slightly wet (not wet!) hairless napkin to clean the speaker grid. Do not use sharp objects, because you can damage the speaker membrane or the sensor itself. If the phone is on warranty, it is better not to do self-repair, but to contact the service center.
In extreme cases, if the sensor is physically defective and it is not software-enabled to disable it (for example, third-party apps are blocked on the new version of Android), the only way out is to use a headset or hands-free communication. You can also consider flashing the device to custom firmware (for example, LineageOS), where the sensor drivers are written differently, but this requires skills and deprives you of warranty.