How to turn on the proximity sensor on Xiaomi Mi A2 Lite: the full guide

Why you need a proximity sensor and how it works on the Mi A2 Lite

The proximity sensor in Xiaomi Mi A2 Lite smartphones is a small but critical component that automatically shuts down the screen during phone conversations. When you bring the device to your ear, the sensor captures the obstacle and extinguishes the display, preventing accidental tapping of the cheek or ear. On the Mi A2 Lite, this sensor is integrated into the top of the screen next to the front camera and speaker.

Many users don't even know it exists until they have problems: the screen doesn't go out during a call, buttons are accidentally pressed, or the display doesn't turn on after a conversation is over. 90% of the time, it's not a hardware fault, but a software failure or incorrect settings. In this article, we'll look at how to check the sensor's performance, turn it on (if it's turned off), and what to do if the sensor isn't working properly.

The Mi A2 Lite is a model released under the Android One program, which means it has a “clean” Android without the proprietary MIUI shell. This affects the location of some settings, including sensor parameters. If you have previously used smartphones with MIUI, the menu may seem unfamiliar — but we will show you in detail where to look for the right options.

Where is the proximity sensor on the Xiaomi Mi A2 Lite

The proximity sensor on the Mi A2 Lite is physically located at the top of the screen, to the right of the front camera, a small hole (or area under the glass) that is barely visible to the eye.

• 🔍 Turn on the flashlight and light on the top of the screen – the sensor will look like a tiny black dot or a transparent window.
• 📱 Look at your smartphone from an angle – sometimes the sensor is visible as a small groove.
• 🛠️ If in doubt, use a magnifying glass – the sensor is usually in the distance. ~5mm from the edge of the display.

It's important to understand that the proximity sensor is not a camera or an infrared port, it's based on infrared radiation, it emits an invisible beam and analyzes the reflected signal, and if the beam comes back (for example, from an ear or hand), the system knows that the screen needs to be locked.

Yes, regularly |Yes, but only when there were problems |No, I didn't know it was necessary |No, I'm afraid to hurt-->

How to check the operation of the proximity sensor

Before you set up or turn on the sensor, make sure it works at all. There are several ways to do this:

1. Test call: Call another phone and hold the Mi A2 Lite to your ear.The screen should go out in 1-2 seconds.Take the device away - the display will light up again.
2. Manual check through the engineering menu: Open the Phone app. Dial the combination ##4636##. Select Phone Information (or Testing on some firmware). Scroll down to the Sensors block and find the Proximity sensor bar. Close the sensor with your finger - the value should change from 5.0 cm to 0.0 cm.
3. Diagnostic apps: Install Phone Doctor Plus or Sensor Box from Google Play, which will show the status of all sensors, including proximity.

If the sensor does not respond to any of the tests, the problem may be:

• 🧹 Sensor pollution (dust, fat, protective film).
• 🔧 Software failure (following settings, application conflict).
• 💥 Hardware failure (damage after falling or getting moisture).

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If the sensor doesn’t respond to touch, try removing the protective glass or film, which sometimes blocks the infrared signal.

Step-by-step: how to turn on the proximity sensor

In the Xiaomi Mi A2 Lite, the proximity sensor is turned on by default at the system level, but its operation depends on the settings of the phone module. If the sensor is inactive, follow the following steps:

Check call settings | Update firmware |Reset network settings | Clear the phone app cache-->

1. Open your phone settings: Go to Settings → System → Gestures → Call settings (the path may vary slightly depending on the Android version).
2. Find the option "Draw-up Sensor": The call menu should have a point "Approximation Sensor" or "Automatic Screen Lock"; if it is not available, use the search by settings (the magnifying glass icon in the upper right corner).
3. Activate the function: Switch the slider to the position On. If the option is missing, then the sensor is controlled at the firmware level (see next step).
4. Update the firmware: Go to Settings → System → Update and check for updates. Sometimes sensor bugs are fixed in new versions of the software.
5. Reset your network settings (if you have a problem after the update): In Settings → System → Reset → Reset your Wi-Fi, mobile network and Bluetooth settings. This won’t delete your data, but it can restore sensors.

If the sensor is still not working after all the manipulations, the cause may be damage to the plume connecting the sensor to the motherboard, in which case a diagnosis is required at the service center.

Frequent problems and their solutions

Even if the sensor is on, it may not work properly, and let's look at the typical scenarios and how to eliminate them:

One of the most common Mi A2 Lite bugs is that the sensor is falsely triggered because of a close-up case or magnetic holders. If you use magnet accessories (like a car holder), try removing them temporarily and checking if the problem persists.

Calibration of the proximity sensor

If the sensor is working, but it's too late or too sensitive, you can calibrate it.

1. Enter the Engineering Menu: Dial ##4636## and select Phone Information.
2. Find the sensor section: Scroll down to the sensor block and tap on the Proximity sensor.
3. Start calibration: Press Calibrate (or Reset if there is no calibration option). Follow the instructions on the screen - usually close the sensor with your finger and hold for 5-10 seconds.
4. Check the results: After calibration, the Max range should be between 4.0 and 6.0 cm. If it is very different, repeat the procedure.

Some firmware may not have calibration, and resetting sensor settings via ADB will help:

adb shell settings put system proximity_offset 0

This command resets the sensor to factory values, and it requires USB debugging and ADB drivers installed to do it.

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Calibration of the proximity sensor is not a panacea; if the sensor is physically damaged (for example, after a fall), software methods will not help, in which case the sensor or the plume will need to be replaced.

Hardware malfunctions: when without service can not do

If all software methods have been tried, but the sensor still doesn't work, the problem is probably hardware.

• 🚨 The sensor does not respond even after resetting the settings.
• 💧 On the screen in the sensor area, traces of oxidation or moisture are visible.
• 🔌 The phone fell or was subjected to severe vibrations (for example, in a backpack without depreciation).
• 🔧 In the engineering menu, the sensor is displayed as Not available.

In the Xiaomi Mi A2 Lite, the proximity sensor is combined with the front camera plume and speaker, which means that replacing the sensor alone is often impossible – you have to change the entire module. The cost of repairs in service centers varies from 1,500 to 3,000 rubles (2026), depending on the region and the availability of original spare parts.

⚠️ Warning: Don't try to disassemble a smartphone yourself to replace the sensor unless you have experience with microelectronics. A2 Lite is extremely fragile and easily damaged if dismantled carelessly, which can lead to additional repair costs.

If you still decide to try to fix the device yourself, be sure to:

• 🛒 Buy the original plume (article for Mi) A2 Lite — MDY07J).
• 🔧 Use plastic blades for disassembly, not metal screwdrivers.
• 📸 Take a picture of each stage of disassembly – this will help to properly assemble the device back.

FAQ: Frequent questions about the proximity sensor on the Mi A2 Lite