Setting up the proximity sensor on Xiaomi Redmi 9T: instruction and troubleshooting

The proximity sensor in the Xiaomi Redmi 9T is a small but critical element that automatically shuts down the screen during phone calls. When you hold your smartphone to your ear, the sensor registers the obstacle and extinguishes the display, preventing accidental pressing and saving battery power. However, many users face problems: the screen does not turn off when talking, the sensor is triggered with a delay or does not work correctly after updating MIUI.

In this article, we will discuss how to properly configure the proximity sensor on the Redmi 9T, manually calibrate it, and fix typical malfunctions. You will learn where the sensor is in the phone case, how to check its performance without special applications, and what to do if the sensor ceases to function after falling or getting moisture, and we will focus on software failures associated with the MIUI 12/13/14 firmware and how to fix them without visiting the service center.

If your Redmi 9T suddenly stops turning off the screen during calls or locks for no reason, don’t rush to carry it for repair. 80% of the time, the problem is solved by setting up the system or cleaning the connectors. Next, you will find step-by-step instructions with illustrations and videos, as well as answers to frequent questions on the topic.

Where is the proximity sensor on Xiaomi Redmi 9T?

On the Xiaomi Redmi 9T, the proximity sensor is located at the top of the screen, to the right of the speaker for conversations. Visually it is impossible to see - the sensor is hidden under the display glass and is a miniature infrared module. To accurately determine its position, shine a flashlight on the top frame: the sensor will look like a small dark spot (about 2×3 mm) next to the front camera.

It's important to understand that the proximity sensor is paired with a light sensor that automatically adjusts the brightness of the screen, and both are placed in the same module, so when you mechanically damage the upper body (for example, after a fall) often fail at the same time, and if you stop working both functions, the problem is likely hardware.

• 📍 Exact location: to the right of the speaker, under the screen glass.
• 🔍 How to find: illuminate with a flashlight - the sensor will look like a dark spot.
• ⚠️ Careful: Don’t confuse with a front-facing camera or notification LED.

On some Redmi 9T versions (for example, for the Indian market), the sensor can be shifted to the left by 1-2 mm. To verify its location, use the sensor test through the engineering menu (instructions below).

How to check the operation of the proximity sensor?

Before you set up the sensor, make sure it's working, and there are a number of ways to do that, from standard MIUI tools to third-party applications, starting with the simplest method, which doesn't require any additional software.

Turn on the phone (you can call another number or use a voice assistant) and hold your palm to the top of the screen.

• 📱 The screen will go out 0.5-1 seconds after approaching.
• 🔄 When you pull your hand, the display will light up again.
• ⏱️ The delay between the activations does not exceed 1 second.

If the screen is not responsive or is not acting as if it is not responding (e.g., it goes out with a delay of 3-5 seconds), then the sensor needs to be adjusted or calibrated.

Open the phone app and type ##4636##

Go to the tab "Phone Information"

Scroll down to the Sensor Block.

Click on "Approximation sensor test"

Put your hand to the top of the screen, and the value should change from 5.0 to 0.0.

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If the sensor does not respond to the approximation in the engineering menu (the value remains 5.0), this may indicate:

• 🛠️ Sensor contamination (dust, greasy prints under glass).
• 💻 Software failure after update MIUI.
• 🔧 Mechanical damage (glass crack, moisture ingress).

Never checked |Only when problems arise |Regularly, once a month |Using special apps-->

Step-by-step adjustment of the proximity sensor

If the sensor is physically healthy but not working properly (for example, the screen goes out with a delay or does not turn on after the phone is taken away from the ear), it can be reconfigured through the standard MIUI settings.

1. Open the Settings. → System system → Additionally.
2. Select the Special Opportunities item.
3. Scroll down and press Automatic Screen Shutdown.
4. Make sure the slider is activated (should be blue).If the option is disabled, the proximity sensor will not work.
5. Go back to Settings → Applications → Application Management.
6. Find the Phone app, open its settings and check the permissions: it should have access to the Body Sensors.

If after these manipulations the sensor is still working with a delay, try resetting the settings of the Phone application:

1. Go to Settings → Applications → Application Management → Phone.
2. Click Warehouse → Clear the data and Clear the cache.
3. Reboot your smartphone.

These actions will return the standard call parameters, including the proximity sensor, and if the problem persists, proceed to calibrate through the engineering menu.

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Once you clear the phone application data, you'll need to reconfigure the quick dial and call history, and save the important numbers to your contacts in advance.

Calibration of the proximity sensor through the engineering menu

Calibration helps to eliminate software failures of the sensor that occurred after the MIUI update or reset. For Xiaomi Redmi 9T, the process is different from other Xiaomi models, so follow the instructions carefully:

1. Open the Phone app and enter the combination ##6484## (this is the code for testing sensors).
2. In the menu that appears, select Proximity Sensor.
3. Press Calibrate. The smartphone will ask you to put it on a flat surface and not touch it for 10 seconds.
4. After the process is complete, check the sensor by holding your hand to the top of the screen.

If the engineering menu doesn’t have a calibration option or the sensor doesn’t respond to commands, try an alternative method:

• 📱 Install the Sensor Test app from Google Play.
• 🔍 Run the proximity sensor test and watch the change schedule.
• ⚙️ In the application settings, find the option Reset Calibration (reset calibration).

After calibration, restart your smartphone. If the sensor is still not working, a hardware malfunction (such as a plume detachment or chip damage) may be the cause.

Solving proximity sensor problems

If the sensor still doesn’t work properly after adjustment and calibration, the reasons may be as follows:

Pay special attention to safety glasses and covers. Many Redmi 9T accessories don't have a proximity sensor cutout, which leads to false positives. If you've recently put on a new glass or installed a case, try temporarily removing them and testing the sensor.

⚠️ Warning: If the sensor stopped working after a phone drop or moisture hit, don't try to disassemble the smartphone yourself. 9T The proximity sensor is integrated into the display module, and its replacement requires special equipment.

What if the proximity sensor doesn’t work after the MIUI update?

One of the most common causes of sensor malfunction is software errors after a firmware update, especially for the Redmi 9T when it comes to MIUI 13/14, where the logic of the sensors changes. Here's how to get things back to normal:

1. Reset the settings of the application "Phone" (instructions given above).
2. Roll back the firmware to the previous version via Settings → About Phone → System Update → Three Dots (menu) → Select the service pack. Download the old version of MIUI from the official Xiaomi website and install it manually.
3. If rollback is not possible, try clearing the system cache: Turn off the phone. Press the Power button + Volume up until the Mi logo appears. From the Recovery menu, select Wipe & Reset → Wipe Cache. Reboot the device.

After upgrading to MIUI 14 on some Redmi 9T, the proximity sensor may conflict with the "Rise to Wake Up" function. To fix the problem, turn off this option in Settings → Screen → Rise to Wake up.

If none of these methods work, the last option is to reset your settings completely, and before that, make sure to save important data, because all files will be deleted.

1. Go to Settings → About the phone → Reset settings.
2. Choose to erase all data.
3. Confirm the action and wait for the reboot.

In such cases, a replacement of the display module is required, since the proximity sensor in the Redmi 9T is soldered into the screen.

⚠️ Note: When replacing the display in unofficial services, there is a risk of installing a non-original module with a poor proximity sensor. Before repair, check with the wizard what screen will be used and ask for a warranty of at least 6 months.

FAQ: Frequent questions about the proximity sensor on Xiaomi Redmi 9T