How to set up the proximity sensor on Xiaomi Redmi 9: the complete guide

The proximity sensor problem on Xiaomi smartphones is one of the most common and annoying. Owners of the Redmi 9 often face a situation where during a conversation the screen goes off on its own or, on the contrary, does not turn off, and the interlocutor accidentally presses the turn off or volume buttons with his cheek. This is due to software failures in the sensor or contamination of the protective glass. It is critical to know that on the Redmi 9 the sensor is software (virtual), not physical, so its operation can be completely reconfigured through a hidden menu.

Don’t panic or take the device to the service center, as most of the time the malfunction is software-based. The MIUI operating system on Redmi 9 has built-in tools for diagnostics and forced calibration of the equipment. Properly configured will allow you to return the comfort of using the phone when making calls in just a few minutes, without the need for third-party software.

Next, we'll go through all the methods available to solve this problem in detail, and you'll learn how to get on the engineering menu, how to do the right reading reset, and what to do if standard methods don't work. It's important to do everything consistently to avoid errors in the system settings. Carefulness at every step guarantees a successful outcome.

Diagnostics and check of sensor performance

Before you start taking active tuning actions, you need to make sure that the problem really lies in the software failure, not mechanical damage. Redmi 9 uses virtual sensor technology that reads data from the accelerometer and gyroscope, and analyzes changes in lighting. If the top of the screen is broken or has severe cracks, this can distort the readings.

For the initial check, you can use the built-in testing mode, which is a secure method that doesn't require root rights or make changes to the system, you have to open the standard Phone application and enter a special combination of characters, and once you enter the code, the CIT engineering check menu will open.

In the test list, find the item associated with the Proximity Sensor. Cover the top of the screen with your palm, and then remove it. If the value changes from 5.0 to 0.0 (or vice versa), then the sensor is physically healthy, and the problem lies in the calibration. If the numbers do not change at all, you may need a deeper diagnosis or repair.

⚠️ Note: If you notice that the sensor only reacts when you press the screen strongly, this may indicate physical damage to the plume or the display module itself.

Engineering menu and code for resetting calibration

The most effective way to fix the bug is to force a reset calibration through an engineering menu, a technique that is common for Android and MIUI devices, which resets the current sensor settings and forces the system to re-determine the zero point (when nothing closes the screen) and the trigger point.

To start the procedure, open the Phone app and enter the code ##6484##. If the code didn't work, try the alternative ##4636##, although the first code is the primary one for Xiaomi. Once you enter the last digit, the menu should open automatically.

In the CIT Menu list that opens, look for the Proximity sensor. Click on it. You'll see a screen with numerical values and two buttons at the bottom. Your task is to press the Calibration button. At which point the phone can vibrate or emit audible signals. Don't touch the screen or talk to the microphone during the process.

Once the automatic procedure is complete, you will see a Pass message (Successful) or Fail message (Error). If the test is passed, be sure to press the Pass button at the bottom of the screen to save the results. If you just leave the menu, the settings may not apply. Reboot the device to take effect.

Setup through the developer menu and debugging

Sometimes standard calibration isn’t enough and requires intervention in deeper system settings through the developer menu.This section is hidden by default so that regular users don’t accidentally change important settings that affect the stability of Redmi 9.

To activate access, go to Settings → About Phone. Find the MIUI Version bar and quickly click on it 7-10 times in a row. You will be notified, "You became a developer." Then go back to the main settings menu, select Additional → For developers.

Inside the developer menu, scroll down to the Input or Hardware section. We're interested in the option to Show Touch or Debug via USB. Although they don't directly calibrate the sensor, enabling the Pointer location option can help visualize the sensor's performance in real time. However, the main method here is to find the Disable proximity sensor on pocket if the problem occurs when you're removing the phone.

⚠️ Warning: Do not change the settings in the developer menu unless you are sure of their purpose. USB It can reduce the security of the device when connected to public charging stations.

If you don't find the options you need, try resetting the developer menu itself. There's a reset button (arrow or cross) at the top of the screen. Once reset, reset only the items you need. Different versions of MIUI (Global, China, EU) may have different locations.

Third-party calibration and control applications

If Xiaomi’s built-in tools don’t work, you can use the proven utilities from the Google Play Store.These apps often have more flexible customization algorithms and can force the system configuration files to be overwritten.

One of the most popular solutions is the Proximity Sensor Reset & Calibration app, which is a forced reset application, and when you install it, you run the app, you put your phone on a flat surface, and you press the Calibrate button, and it asks you to close the sensor, and then you open it, fixing the values.

Another useful application is the Phone Sensor, which allows you not only to calibrate, but also to completely disable the proximity sensor in a software way, and this can be a temporary solution: you turn off the sensor when it interferes, and turn it back on when you need it, which is true if the sensor is physically damaged, but you don't plan to change the screen yet.

Using third-party software is safe if you download it from official sources, but remember that such applications may require unnecessary permissions. Carefully read what data the program accesses before installing.

Removing false positives and protecting the screen

A common cause of proximity sensor problems on Redmi 9 is protective glass or low quality films. If the glass has a black frame at the edges or is offset by the sticker, it can overlap the sensor area located in the upper left or right corner (depending on the regional version).

Try to carefully remove the protective coating and check the phone without it. If the problem disappeared, then it was the accessory, in which case it is better to buy a new glass with a cutout for the sensor or a quality film that does not have darkening at the top.

Also worth noting is the case. Some covers have high sides that, when they're tightly attached to the ear, can mechanically press on the sensor area or create a shadow. Take off the case and check the sensor's performance in the naked form.

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Use the "Mode in your pocket" function with caution. If it does not work properly, it is better to turn it off in the lock settings of the screen to avoid accidental pressing.

Another nuance is pollution: Fat spots from the conversation or dust can accumulate in the speaker grid, closing the sensor. Wipe the top of the screen with a microfiber slightly soaked in an alcohol solution (make sure that the liquid does not get inside).

Alternative solutions and resetting settings

When neither calibration nor removal of the security glasses helps, there is a software reset option, which is a radical method that returns all system settings to factory values. Before that, make sure to back up all important data, as the information will be deleted.

Go to Settings → Advanced Settings → Restore and Reset. Select Reset. The phone will reboot and start the cleaning process. Once turned on, the proximity sensor will be recalibrated to factory settings.

If even a full reset doesn't solve the problem, it might be a bug in a particular version of MIUI. Check for system updates in the About Phone menu. Often developers release patches that fix sensor drivers. Install the latest available firmware.

⚠️ Warning: Full reset will delete all your contacts, photos and apps. Make sure that sync with Mi Account and Google Account is successful before starting the procedure.

In extreme cases, if the software methods are powerless, it can be a failure of the display module. On the Redmi 9, the sensor is integrated into the screen plume, and its replacement requires qualified intervention in the service center.

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A comprehensive approach: removing the protective glass + code calibration + firmware update solves 95% of sensor problems on the Redmi 9.

Frequently Asked Questions (FAQ)