Xiaomi’s Redmi series is famous for its value for money, but the MIUI software shell sometimes brings unpleasant surprises. One of the most common problems faced by owners of the Redmi 9T is the incorrect operation of the proximity sensor. The screen can go out during a conversation, do not light up when you bring the phone to your ear or, conversely, constantly glow in your pocket, causing accidental pressing.
Many users immediately look for a way to turn off the sensor completely, believing that this will solve the problem. However, in the standard Android and MIUI settings menu, this option is often absent or hidden from the eyes of the average user. It is important to understand that completely disabling the sensor can lead to inconveniences, such as accidental resets of calls with the cheek, but in some cases this is the only solution to software conflicts.
In this article, we will take a look at all the sensor deactivation methods available, from simple switches in the engineering menu to using third-party apps. You will learn why your Redmi 9T behaves strangely during calls, and how to fix the situation without losing warranty or complex flashing the device.
The reasons for the incorrect operation of the sensor on the Redmi 9T
Before you go to extreme lengths to disable the device, you need to understand the root of the problem. The proximity sensor on the Xiaomi Redmi 9T is an infrared emitter and receiver located at the top of the case, often hidden under the speaker or in a thin frame, its main task is to determine the distance to the object and turn off the display when the phone is held to the ear.
A common cause of failure is software conflict after an operating system update. The new version of MIUI may miscalibrate the sensor's sensitivity, causing it to react to the slightest changes in lighting or stop signaling the system altogether, and may also be affected by low-quality protective glass that blocks the IR radiation, or banal contamination of the upper part of the screen.
There's also the hardware aspect: when you drop or get moisture, the contacts of the sensor could oxidize or move away. However, if the phone wasn't physically exposed, it's probably the software, and in these cases, users often decide to turn off the sensor so that it doesn't interfere with the device, even if that means manually controlling the screen while talking.
- 📱 Software failure after firmware update MIUI.
- 💧 Getting moisture or dirt in the area of the upper speaker.
- 🛡️ Use of protective glass covering the sensor.
- 🔧 Physical damage to the plume or the sensor module itself.
⚠️ Warning: A complete shutdown of the proximity sensor means that the phone screen will no longer go out automatically when approached to the ear.This can lead to accidental tapping of the cheek or ear during a conversation.
Checking the performance through the engineering menu
The first step before any interference with the system should be diagnostics, and the MIUI's cover includes a hidden engineering menu that allows you to test all hardware components, including sensors, to help you understand whether the sensor is physically working or whether the problem is solely in the logic of the system.
To enter the test mode, you need to open the standard Phone app and dial a special command. Dial the code ##6484## on the dial keyboard. Once you enter the last star or grille (depending on the regional version), the CIT (Customer Information Test) menu will open. Here is a list of all the modules tested.
Find the item "Proximity sensor" or "Proximity sensor" in the list. Click on it to start the test. You'll be asked to close the top of the screen with your hand. If the sensor is working, the value on the screen will change from "Far" (far) to "Near" (close), and the phone will emit an audible signal. If there is no reaction, the problem may be hardware, and software shutdown will be the only way out.
It is important to note that in some versions of the firmware access to CIT-If the code didn't work, try entering ##4636##, although this code is more commonly used to test the network, in some builds it also gives access to diagnostics.
Sensor calibration as an alternative to shutdown
Before you deactivate the sensor completely, you should try to calibrate it. Often it happens that the sensor just "lost" and thinks that the object is close, when in fact it is not. Calibration returns factory sensitivity parameters and in many cases eliminates the need for shutdown.
There are several ways to calibrate on the Redmi 9T. The easiest one is through the same CIT engineering menu. Select the proximity sensor test, remove your hand from the screen (to show "Far"), and press the "Calibrate" or "Pass" button, after which the phone may ask you to close the sensor and open it again several times to record new values.
If the standard method doesn't work, you can use a secret code to reset the calibration ##64663## (The code may vary depending on the version. MIUI). There is also a method through the developer menu, but it requires the inclusion of debugging by USB. To do this, go to the Settings. → On the phone and press quickly 7-10 once under “Version” MIUI».
💡
If calibration through the CIT menu doesn't help, try removing the protective glass and rubbing the top of the screen with an alcohol wipe - fat spots often block the IR ray.
After successful calibration, be sure to restart the device. Reset is necessary in order to ensure that the new sensor profile applies to all system processes, including the Phone application and screen lock.
Disconnection through hidden MIUI settings
In some versions of Xiaomi firmware, there is a hidden switch that allows you to ignore the proximity sensor readings during calls. This feature is not conspicuous and often hidden in the depths of the settings of the Phone application or in special features.
To find this option, open the Phone app, click three dots in the corner or the menu button, and select Settings. Look for Incoming Calls or Additional Settings. There may be a point called Approximation Sensor or Turn off the screen while you talk. When you tick off the box, you will actually turn off the system's response to the sensor.
However, in the latest versions of MIUI 12 and MIUI 13 installed on Redmi 9T, this item is often hidden, in which case you can try to activate the hidden settings menu. To do this, in the Phone application, type ##86583##. If you see the message "Remote log level DISABLED", then the hidden settings were already active. If "ENABLED" - then they were turned on and the code turned them off (you need to re-enter).
Once you activate the code, go back to your phone's settings and find "Additional Settings" → "Developers" (if it's available) or go back to your call settings. Sometimes it's there. This method doesn't work on all regional firmware, but it often works on global Xiaomi versions.
| Method | Difficulty | Efficiency | Risk of failure |
|---|---|---|---|
| Engineering Menu (CIT) | Low. | Medium | Minimum |
| Hidden MIUI code | Medium | Tall. | Low. |
| Third-party annexes | Low. | Tall. | Medium. |
| Root rights (Build.prop) | Tall. | 100% | High-pitched |
Use of third-party applications for management
If the built-in tools fail to solve the problem, applications from the Google Play store come to the rescue. There are many utilities that can intercept the control of the proximity sensor and force the screen to turn on or off according to the given rules, ignoring the system settings of Xiaomi.
One of the most popular solutions is the Proximity Sensor Reset & Fix app or equivalents like Lesser Notification Icons. Once you install it, you need to give it extended access rights. On the Redmi 9T with active MIUI protection, you will need to allow auto-start and work in the background, otherwise the system will kill the process in a few minutes.
Some applications allow you to create a "During a Call" profile, where the proximity sensor is ignored software, so you just launch the app before an important conversation, which is less convenient than a system solution, but it does not require superuser rights and does not make changes to system files, which is important for maintaining warranty.
☑️ Checking before installing applications
Be careful when choosing such software. Many free applications are full of ads or may contain malicious code. Always check the developer and read the latest reviews, as after Android updates, older versions of programs may stop working correctly.
Radical method: changing system files (Root)
For power users who are not afraid to lose warranty and are willing to take risks, the most reliable way is to edit system files. This method requires Root rights (superuser rights) and an unlocked bootloader. On Redmi 9T, this means waiting 168 hours after submitting an application to the Mi Unlock Tool.
The method is to change the build.prop file or create a special configuration file that tells the system that the proximity sensor is missing, as a result, the driver stops polling the sensor, and the screen behaves as if it is physically absent. To edit files, you will need a file manager with root access, such as Root Explorer or Root Explorer. MT Manager.
Add ro.proximity.disabled=1 (the setting may vary depending on the Android version) to the appropriate configuration file section. After making changes, the phone must be rebooted. If the setting is entered incorrectly, the device can go into an endless bootloop, so having a backup or the ability to flash through the Fastboot is critical.
⚠️ Note: Editing build.prop system files without a backup can make it impossible to boot the system.Do this only if you are confident in your actions and have an unlocked bootloader.
This is the only 100% solution for those who are constantly disturbed by the sensor and software crutches do not help, but given the complexity of obtaining Root rights on modern versions of MIUI, it is not suitable for all owners of Redmi 9T.