How to check the proximity sensor on your Xiaomi smartphone: from simple tests to the engineering menu

The proximity sensor in Xiaomi smartphones is a small but critical component responsible for turning off the screen when you hold the phone to your ear. If it doesn't work properly, you run the risk of accidentally pressing the buttons with your cheek, draining the battery faster due to the constant backlight of the screen or skipping the call altogether. 10/11/12, POCO X3/X4 and flagships of the Xiaomi series 12/13, where the sensor often fails after falls or updates MIUI.

In this article, we will discuss 5 working ways to check the proximity sensor, from standard tests to hidden engineering menus that service centers use. You will learn how to detect a malfunction without special equipment, which applications give the most accurate results, and what to do if the sensor only “gluts” during calls.

1. Quick check through standard call

The easiest way to diagnose is to simulate real-world usage. You don't need apps or codes, just the smartphone itself and 30 seconds of time. This method is suitable for all Xiaomi models, including the Redmi 9A, POCO M3 and Mi 11 Lite.

Here's how it works:

• 📞 Open the Phone app and dial the combination for a test call (e.g. #12345# is a secure number that a real subscriber will not dial).
• 👂 As soon as it rings, hold the phone to your ear (or simply cover the top with your palm where the sensor is located).
• 🔍 The screen should go out instantly. If it stays on or goes out with a delay of more than 1 second, the sensor is defective.
• 📱 Remove your hand from the screen: the backlight should return immediately. Lag of more than 0.5 seconds also indicates a problem.

⚠️ Attention: On some firmware MIUI (Especially in the global market versions, the screen may not go out during dialing, but it should react when a real call is made. If the test doesn't work, try calling another phone.

2. Hidden service codes for sensor testing

Xiaomi hides engineering menus from users, but they can be opened with the help of special devices USSD-These codes work on most models but the newest (e.g. Xiaomi 14 may require other combinations). Importantly, the codes will not delete data, but do not enter it on custom firmware phones, which can cause a crash.

Basic codes for checking the proximity sensor:

• 🔢 ##6484## - Sensor test (on some models shows the status of Proximity Sensor).
• 🔢 ##4636## → Phone information → Scroll down to the Sensor Block.
• 🔢 ##64663## - Alternative sensor test (works on the sensors) POCO F3, Redmi K40).

Once you enter the code, you'll see a screen with a graph or a digital value, and here's how to interpret it:

• 📊 0 - The sensor does not detect the obstacle (it is normal when the phone is lying on the table).
• 📊 1 or 5 – the sensor is triggered (should appear when you close the top with your palm).
• 📊 Constantly 0 or 1 – the sensor “freeze” in one state (requires repair).
• 📊 Jumping values (0)→1→0) - interference or poor contact of the plume.

3. Applications for deep diagnostics

If the service codes didn't work or you want more information, use third-party apps that not only show the current state of the sensor, but also store the log of its operation, which is useful for analyzing periodic failures. We tested 7 applications and selected the 3 most reliable ones:

🔧 How to use it:

1. Install one of the applications (we recommend Sensor Box for detailed analysis).
2. Open the Sensors or Proximity section.
3. Cover the top of the phone (where the listening grille is located) with your palm.
4. The graph should show a green line (activation), and if the line is red or missing, the sensor will not work.

Make sure there is no cover or film on the phone in the sensor area.

Close all background applications (they may interfere with the test)

Check that the screen brightness is set to 50% or higher

Do not keep your phone in direct sunlight (infrared sensor may crash)-->

4. Verification through the Engineering Menu (MTK and Qualcomm)

This is a method for power users, and the menu of engineers gives you access to low-level sensor settings, including calibration and testing of the hardware, and be careful, if you do something wrong, you can crash the firmware.

Instructions for Qualcomm processors (most Xiaomi and POCO):

1. Enter the code ##4636## → select Phone Information.
2. Scroll down to Sensors and find the Proximity Sensor string.
3. Click on it and the graph will open with values 0 (no obstacle) and 1 (there is an obstacle).
4. To calibrate, press Calibrate (if the option is available).

For MediaTek processors (e.g. Redmi 10A, POCO C31):

1. Enter the code ##36446337## (or #3644633## for older models).
2. Go to Hardware Testing → Sensors.
3. Select Proximity Sensor and follow the instructions on the screen.

⚠️ Note: On some Xiaomi models (e.g. Mi 11 Ultra), the engineering menu may require a password. The standard password is 1234 or 0000, but if it does not fit, do not try to pick it up - after 3 unsuccessful attempts, the menu will be blocked.

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If the engineering menu isn’t available, try using the MTK Engineering Mode app (for MediaTek) or the Qualcomm Engineer Mode from Google Play. They simulate service features without entering codes.

5. Hardware check (without disassembling the phone)

If software methods have failed, but you suspect a physical sensor malfunction, follow these steps before visiting the service center:

Signs of hardware damage:

• 🔦 The sensor does not respond to any of the tests, but is defined in the engineering menu as "connected».
• 💥 The phone fell or was exposed to moisture (even if there is no external damage).
• 📉 The problem occurred after the replacement of the screen or battery (possibly damaged the plume).

What you can do on your own:

1. Check the cover and the film, even a thin film in the sensor area can block the infrared signal, remove the case and repeat the test.
2. Look at the listening grate. Clogged holes (dust, dirt) interfere with the sensor's operation. Clean them with a soft brush (do not use alcohol-containing liquids!).
3. If the phone was deconstructed, the sensor plume could have moved away: 🛠️ Carefully remove the back cover (for models with removable body, for example, Redmi). 9C). 🔌 Find the plume running from the top of the board to the sensor (usually black or gray). 🖐️ Easy press it – if the contact is restored, the sensor will work.

Critical information: On the Xiaomi 12 Pro and 13 Pro, the proximity sensor is combined with the light sensor in one module, and if both are not working, you need to replace the entire unit, rather than a separate sensor.

Typical errors and their solutions for specific models

Some of the proximity sensor issues are unique to certain Xiaomi lines, and we’ve gathered data from 4PDA service centers and forums to help you find a solution faster.

💡 If your model is not in the table, check the official forum Xiaomi – there often publish branded fixes for new devices.

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In the models with AMOLED-screens (e.g. Xiaomi) 12T) The proximity sensor may conflict with the Always-On Display function. AOD in the screen settings, if the sensor is triggered arbitrarily.

FAQ: Frequent questions about the proximity sensor on Xiaomi