Disable the proximity sensor on Xiaomi Redmi 9T

Owners of the popular Xiaomi Redmi 9T budget smartphone often face the unpleasant situation when the screen goes out during a conversation and stops responding to touch. This is a classic symptom of the incorrect operation of the proximity sensor, which mistakenly thinks that the phone is near the ear, even when you hold it at a distance, as a result, the interlocutor hears you, but you can not complete the call or turn on speakerphone until the screen lights up again.

The problem is not only relevant for older models, but also for devices released in recent years, including the Redmi Note 9 series and Redmi 9T. The reason lies in both software failures of the MIUI shell and the design features of the sensor itself, which can be contaminated or misplaced. Fortunately, the Android system and the Xiaomi brand add-on provide several ways to solve this problem, from simple settings to using an engineering menu.

In this guide, we will take a look at all the available methods, from basic screen cleaning to hidden engineer codes. You don’t have to be a technician to fix the situation. We will look at the regular shutdown tools that are available to every user, as well as more advanced options for those who want to fully control the operation of their device’s hardware sensors.

Why the proximity sensor is not working properly

Before we go into radical measures and shut down the function, we need to understand the nature of the bugs. The proximity sensor on the Xiaomi Redmi 9T is an infrared sensor located at the top of the display. It emits invisible light and analyzes its reflection from objects. If a protective glass, dirt or even a finger is in the path of the beam, the system receives a signal that the phone is pressed to the head.

Often, the culprits are poor-quality protective films or glass that cover the sensitive area, even a microscopic layer of grease or dust can distort readings, and software conflicts after an operating system update can cause calibration to go wrong, and the trigger threshold becomes too sensitive.

⚠️ Attention: If the screen only goes out in certain cases, the problem may be their design. Too thick or high side of the case can physically overlap the sensor, simulating the approach of the object.

Sometimes the failure is temporary and is associated with overheating of the processor or prolonged operation of background applications. In such cases, a simple reboot of the device can temporarily return the sensor to normal, but to ensure the result will require a deeper intervention in the settings of the system.

Using the Engineering Menu for Diagnostics

The most reliable way to check the state of the sensor and try to fix it without third-party software is to use the built-in engineering menu. This is a hidden part of the system, designed to test the hardware, on Xiaomi smartphones, access it through a special code that works on most models, including the Redmi 9T.

To enter the menu, you need to open the standard Phone app and dial ##6484#. Once you enter the last digit, the screen will automatically switch to CIT (Customer Integration Test) mode. Here is a list of all the components of the device, and you need to find the item associated with the Proximity Sensor and click on it.

In the window that opens, you'll see the current readings of the sensor, and if you close the top of the screen with your hand, the value should change (usually from 5.0 to 0.0 or vice versa, depending on the firmware version), if the values do not change or jump randomly, this indicates a physical malfunction or severe contamination, and if the test is successful, but the problem persists, then software calibration or reset is required.

Some versions of MIUI firmware have a Calibration or Start button right in this menu. Press it and follow the instructions on the screen: usually close the sensor with your hand, then remove your hand and press the confirmation button, and after successful calibration, the device will notify you of this, and you can exit the menu.

Disconnection through call settings

The simplest and safest method, which requires no special knowledge, is to turn off the lock function during a conversation through standard settings, which does not physically deactivate the sensor itself, but prevents the system from responding to its signals by quenching the display, which is the ideal solution for those who do not want to risk the stability of the phone.

To do this, open the Phone app and click on the three dots in the top right corner (or menu button). Select Settings. In the list that opens, look for Incoming Calls. That's where the switch that controls the screen behavior hides.

Find the Proximity sensor option and put the slider in an inactive position, and now the screen will burn constantly during the call, so you can complete calls or change the volume at any time, but it is worth remembering that this increases the risk of accidentally pressing the cheek on the reset buttons or changing the volume.

If you don't find one on the menu, your version of the MIUI shell may be hiding this option, so you can try an alternative route: go to General Settings → System and Device → Lock and Protect (the path may vary depending on the Android version).

Application of third-party applications

When the standard tools are not helpful or hidden by the manufacturer, Google Play apps come to the rescue. There are many tools designed specifically for managing sensors on Android, which work on top of system settings and allow you to force the sensor to turn off or change the sensitivity of its operation.

One of the most popular and proven solutions is Proximity Sensor Reset/Fix or its counterparts, like Proximity Service, and once you install it, you have to give it the permissions you need, usually phone access and system settings.

The interface of these programs is usually extremely simple: one large Disable or Enable button. Once clicked, the application can request confirmation through the Android pop-up. If you unload them from memory, the feature can work again.

Reset sensor settings via ADB

For advanced users who are not afraid to work with a computer, there is a method of disabling the sensor through the ADB debugging bridge (Android Debug Bridge), which allows you to make changes to system databases that are not available through a regular interface, and it is effective when other methods do not work.

First you need to activate the developer mode on Xiaomi Redmi 9T. To do this, go to the Settings. → About the phone and quickly press 7 times on the item "Version" MIUI». After the message “You became a developer” appears, go back to the settings menu, find “More» → «For developers" and include the item "Debugging by USB».

Connect your smartphone to your computer through USB-You need to have a platform platform on your PC. Open the command line in the folder with ADB and enter a command to check the connection:

adb devices

If the device is determined, you can enter a command to change the value of the sensor. However, there is no universal command to completely disable, since it depends on the drivers.

adb shell settings put system proximity_on 0

Or by changing global parameters:

adb shell settings put global proximity_sensor_enabled 0

⚠️ Attention: Use ADB It's very careful, and if you don't get the right commands, you can get the system to be unstable or you can lose data.

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Before using ADB, make sure to make a full backup of important data to a cloud server or computer, as interference with system settings always carries risks.

Mechanical causes and cleaning

And remember, software shutdowns are just a side effect, and if the sensor is contaminated, it's not going to be correct even after it's reset. On the Redmi 9T, the proximity sensor is often paired with a speaker speaker, and it's in a narrow gap at the top of the screen, and it's easy to stuff dust, pocket pile, and skin fat.

To clean, use a soft toothbrush or cotton swab lightly soaked in isopropyl alcohol. Walk gently along the top of the device. Do not use sharp objects such as needles or toothpicks, as they can easily damage the speaker's mesh or the sensor itself.

Also, check if there's a protective film on the screen that doesn't match the sensors, sometimes it just helps to remove the film and wipe the glass, and if the phone falls, the sensor could shift inside the case, and then only disassembly and repair in the service center will help.

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Regular hygiene of the top of the smartphone is the best prevention of problems with the proximity sensor, which avoids the need for software interventions.

Frequently Asked Questions (FAQ)