How to calibrate the proximity sensor on Xiaomi Redmi 9: 3 working methods

Why the Redmi 9's proximity sensor is not working properly

The proximity sensor in Xiaomi Redmi 9 is responsible for automatically turning off the screen during a call when you hold the phone to your ear. If it malfunctions, the screen does not go out, buttons are accidentally pressed, or vice versa, the display does not turn on after the conversation is completed. The causes of the malfunction can be either software (calibration failure, MIUI errors) or hardware (sensor contamination, mechanical damage).

In 80 percent of cases, recalibration of the sensor is a procedure that resets the sensor to factory values or reconfigures it to current conditions. On Redmi 9, you can do this in three ways: through a hidden engineering menu, standard MIUI settings, or using third-party applications. It is important to understand that calibration will not help if the sensor is physically damaged (for example, after a phone drop or moisture).

Before you start setting up, check if the sensor is disturbed by a protective glass or case. Sometimes even a thin film can block the infrared signal. Also make sure that the problem is not the firmware: update MIUI to the latest version through Settings → About Phone → System Update.

Method 1: Calibration through the engineering menu (without root)

The engineering menu is a hidden settings section where you can test and configure the hardware components of a smartphone. On Redmi 9, it is accessed through a secret code. Warning: do not change the other settings in this menu unless you understand their purpose - this can cause malfunctions in the phone.

To open the engineering menu and calibrate the proximity sensor:

1. Open the Phone app.
2. Enter the combination ##6484## (some firmware may run ##4636##).
3. Select Proximity Sensor (Proximity Sensor).
4. Press Calibrate and follow the instructions on the screen.
5. Once completed, restart the phone.

If the code doesn’t work, try an alternative:

##36446337##

Charge your phone at least 30%

Make sure that the sensor does not receive direct light

Close all background applications

Do not interrupt the calibration process-->

⚠️ Note: On some versions MIUI If nothing happens after you enter the code, try using method 2 or 3.

After calibration, check the sensor, call another number and hold the phone to your ear. The screen should go out in 1-2 seconds. If the problem persists, move to the next method.

Method 2: Calibration through MIUI settings (official method)

The latest versions of MIUI (starting with 12.5) have built-in sensor calibration, including the proximity sensor, which is the safest method, since it does not require access to hidden settings.

1. Open the Settings. → The phone.
2. Tap 5-7 times on the MIUI version until you become a developer!
3. Return to the main settings menu and open Additional settings → For developers.
4. Scroll down and find the Sensor Calibration section.
5. Select the Approach Sensor and follow the prompts on the screen.

During calibration, the system will ask:

• 📱 Put your phone to your ear (like when you call).
• 🖥️ Hold it in this position for 5-10 seconds.
• 📵 Put the phone away from your ear and wait a few more seconds.

If the sensor calibration option is not in the developer menu, then your version of MIUI does not support this function, in which case use method 1 or 3.

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After calibration, reset the network settings: Settings → SIM-maps and mobile networks → Reset network settings, which will help to avoid conflicts with the sensor during calls.

Method 3: Use third-party applications (if the first two fail)

If standard methods don't work, you can use specialized applications from Google Play, which offer advanced settings for calibration and testing of sensors.

• 🔧 Proximity Sensor Reset – Resets sensor settings to factory.
• 📊 Sensor Test – checks the performance of all sensors, including the approximation.
• 🛠️ CPU-Z — Provides technical information about sensors (useful for diagnostics).

Instructions for Proximity Sensor Reset:

1. Install the app from Google Play.
2. Open it and provide access to sensors (if requested).
3. Press Calibrate Proximity Sensor.
4. Follow the instructions on the screen (usually you need to bring and take the phone away from your ear).
5. Reset the device.

⚠️ Note: Some apps require root rights. If you don't know what they are, don't try to get them - this can void the warranty and damage the system.

On the Xiaomi Redmi 9, the proximity sensor is located at the top of the screen, to the right of the speaker. If it still doesn't work after calibration, check it for contamination: wipe the area with a soft napkin dipped in alcohol (do not use abrasive materials!).

Through the engineering menu

Through MIUI settings

With a third-party application

Nothing helped.-->

What to do if calibration did not help: diagnosis of hardware problems

If all three of these things don't work, the problem is probably hardware.

To check the operability of the sensor without a call:

1. Enter the number ##0*##.
2. The component testing menu will open.
3. Select Proximity Sensor.
4. Close the sensor with your hand – the screen should change color (usually from white to green).

If the sensor does not respond even in test mode, this confirms a hardware malfunction, in which case self-repair is not recommended - it is better to contact an authorized Xiaomi service center.

Frequent calibration errors and how to avoid them

Many users make the same mistakes that cause calibration to go wrong, and here are the most common:

• 🌞 Bright light: The Redmi 9's proximity sensor is infrared sensitive, and calibration should be done in a room with normal light, without direct sunlight.
• 🔋 Low battery charge: If the charge level is below 20%, the system can interrupt the process. charge the phone to at least 30%.
• 📱 Protective accessories: High-sided covers or thick glass can block the signal.
• 🤖 Incompatible applications: Some battery-saving software (such as Greenify) may interfere with sensors.

Another common mistake is to interrupt the process, and if you get a call or a notification during calibration, the settings will reset and you have to start the procedure again. To avoid this, turn on Do Not Disturb before you start:

Settings → Notifications and Status Bar → Do not disturb

If the sensor is unstable after calibration (for example, the screen goes out with a delay), try resetting the network settings:

→ SIM-maps and mobile networks → Network reset

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After any calibration of the proximity sensor, be sure to restart the phone, which allows the system to apply new settings and avoid conflicts with background processes.

Alternative solutions if the sensor is not repairable

If the proximity sensor on Redmi 9 finally fails, but you do not want to carry the phone for repair, you can use workaround solutions:

• 📞 Disabling the sensor during calls: In settings MIUI There's an option that allows you to manually control the screen while you're talking. → Annexes → Phone. → Disable the proximity sensor After that, the screen will remain on, but you can block it with the power button.
• 🔄 Headset use: Connect wireless or wired headphones – in this case, the proximity sensor is not involved.
• 📲 Applications for forced screen shutdown: For example, Proximity Screen Off allows you to customize screen behavior during manual calls.

Please note that disabling the proximity sensor may result in:

• Accidental presses during a call (for example, on the call completion key).
• Quick battery discharge (the screen remains on).
• Discomfort when talking (you have to manually lock the phone).

If you decide to turn off the sensor, we also recommend setting the automatic lock delay to a minimum (5 seconds) so that the screen fades faster after the call is completed:

Settings → Lock screen → Sleep after → 5 seconds

FAQ: Answers to Frequent Questions About the Approach Sensor on Redmi 9