How to turn on the proximity sensor on Xiaomi Redmi 9C: a complete guide with photos

The proximity sensor in Xiaomi smartphones is a small but critical element that is responsible for automatically turning off the screen during a phone call. On the Redmi 9C model (codenamed angelica), this sensor sometimes works incorrectly or completely turns off by default, leading to accidental tapping of the screen with the cheek or ear. If you notice that the display does not go out when you bring the phone to the ear, the problem lies in the settings (or hardware malfunction) of the sensor.

In this article, we will discuss how to properly turn on the proximity sensor on the Redmi 9C, where to look for the appropriate options in the MIUI, and also diagnose its performance without special tools. Separately, we will focus on the typical errors of users who try to activate the function through an engineering menu or third-party applications - and why this can lead to the opposite effect. If after all the manipulations, the sensor does not work, you will learn how to distinguish a software failure from a physical failure.

What is a proximity sensor and why you need it

The proximity sensor is an optical or infrared sensor located at the top of the smartphone screen (usually next to the speaker), its main task is to detect when the user brings the phone to the ear during a call, and instantly turn off the touch screen to avoid accidental touch. Without this sensor, you run the risk of:

📞 Interrupt the call with the cheek by pressing the button "Complete the call"
🔊 Turn on speakerphone or transfer the conversation to hold
📱 Run background apps or activate voice assistant

The Redmi 9C uses an infrared sensor that emits invisible light and analyzes the reflected signal. If an object (like your head) is too close, the sensor sends a command to the system to lock the screen. It's important to understand that this sensor only works during calls, because the rest of the time it does not work to save battery power.

In addition, the proximity sensor indirectly affects the operation of the Smart Cover function (if you use a magnet case) and can interact with Raise to Wake gestures. However, its main purpose is to protect against false touch during a conversation.

Where is the proximity sensor on the Redmi 9C

On the Xiaomi Redmi 9C, the proximity sensor is located at the top of the front panel, to the right of the speaker. Visually, it is not visible, it is hidden under the protective glass of the display. To determine its location, look at the front camera (it is in the cutout "drop"): the sensor is on the right of it, about 5 mm from the edge of the screen.

If you want to make sure it's physically present, you can use a flashlight: point a bright light at the top of the screen at an angle, the sensor on can flicker slightly (this is normal for infrared sensors), and you can check its position through the test menu, which we will discuss below.

📊 Have you ever encountered the problem of a broken proximity sensor?

Yes, on the Redmi 9C.

Yes, on another Xiaomi model.

No, but I've heard about this problem.

What is this?

Xiaomi model	Type of sensor	Location	Features
Redmi 9C	Infrared	Right of the front camera.	It only works when you're calling.
Redmi Note 10	Infrared	Under the display, next to the speaker	Supports gestures
Poco X3	Optical	In the screen cutout	Higher accuracy

How to turn on the proximity sensor on Redmi 9C: step-by-step instructions

In most cases, the proximity sensor on the Redmi 9C is activated by default, but sometimes it is blocked due to MIUI failures or incorrect settings. To turn it on manually, follow the following steps:

Open the Settings app (the gear icon on the home screen).
Go to the System Applications section → Calls.
Select Incoming Calls.
Activate the Approach Sensor switch (if you have one in your MIUI version).
If there is no such item, go back to Settings → Screen → Autoturn and sensors and check for the option there.

In some firmware (e.g., Android 10), the path may be different. If you don't find the right item, try an alternative method:

📱 Open the Settings. → The phone.
🔍 Click 5 times in a row on the version MIUI, to unlock the developer mode.
🔧 Back to Settings → Additionally. → For developers.
🔍 Find the option to turn off sensors and make sure it is turned off.

1. Go to the call settings

2. Make sure the sensor is not manually disabled

3. Check the developer mode for blockings

4.Reboot the phone after the changes-->

Important: On some custom firmware (e.g. LineageOS), the proximity sensor may not work due to the lack of drivers, in which case you will need to flash the original MIUI or install a patch through TWRP.

How to check if the proximity sensor is working

If you've turned on the sensor, but you're not sure if it's working, you can do a simple test without any additional applications.

This method is suitable for advanced users and requires caution:

Open the Phone app.
Enter the combination: ##6484### (or #4636## for older versions of MIUI).
Select the Proximity Sensor.
Close the top of the screen with your hand – the value should change from 5.0 cm to 0.0 cm.

If the values do not change or an error is displayed, the sensor is faulty or disabled at the system level.

Method 2: Checking during the call

A simpler and safer method:

Call another phone (or use a voice assistant).
During the call, hold your palm to the top of the screen (where the sensor is located).
The screen should go out instantly.
Remove your hand, the display should light up again.

If the screen is not responding, try repeating the test with the Plane Mode on (to avoid interference from the network), and check if the sensor is disturbed by a protective film or a case with metal elements.

What if the sensor does not respond to the test?

If the sensor fails any of the tests, the reasons may be: 1. Software failure - requires a reset or flashing. 2. Sensor contamination - dust or moisture under the glass blocks the signal. 3. Physical failure - damage after falling or hitting water. 4. shell conflict - some MIUI themes turn off the sensors to save energy.

Typical problems and their solutions

Even after switching on, the proximity sensor on the Redmi 9C may not work properly, and here are the most common symptoms and ways to treat them:

Problem.	Possible cause	Decision
The screen does not go out during the call.	Sensor turned off in settings	Enable in Settings → Calls → Incoming calls
The sensor is working too late.	Sensor contamination or damage	Clean the top of the screen with alcohol
The screen goes out arbitrarily	Conflict with cover or film	Remove the cover and check without it
Tests show error	Damage after falling	Diagnostics at the service center

If the sensor started to glittle after the MIUI update, try rolling back to the previous firmware version or resetting the settings:

Go to Settings → About the phone → Reset settings.
Select Reset all settings (does not delete files!).
After restarting, check the sensor.

💡

If the sensor is unstable, try calibrating it through the engineering menu. To do this, type ##6484##, select Proximity Sensor and press Calibrate.

What to do if the sensor is not turned on

If you've followed all the instructions, but the proximity sensor on the Redmi 9C is still down, it's time for more serious action.

1. Check for hardware damage

Look at the top of the screen for:

🔍 Cracks or chips on the protective glass
💧 Traces of moisture (oxidation of contacts)
🧲 Metal elements in the case that can shield the signal

If the phone falls or comes into contact with water, the sensor is likely to fail, and only if the sensor module is replaced at the service center, it will help.

2. Diagnosis through ADB

For advanced users, you can check the status of the sensor through ADB (Android Debug Bridge), connect the phone to the PC and follow the commands:

adb shell


dumpsys sensorservice

In the output, find the proximity string. If it's not there or if it's unavailable, the sensor is disabled at the system level.

3. Phone flashing

If the sensor stopped working after the MIUI update, try:

🔄 Reverse to the previous version of the firmware via Fastboot.
🔧 Install Global Stable instead of regional firmware.
🛠️ Swipe your phone through the Mi Flash Tool with complete data cleanup.

💡

If the sensor does not work after mechanical damage, it will cost 1,500-2,500 rubles (depending on the service center). Self-repair is not recommended - there is a high risk of damage to the display plume.

Frequent questions about the proximity sensor on the Redmi 9C

Can I turn off the proximity sensor if it interferes?

Yes, but it's not recommended. If the sensor is annoying (e.g., the screen goes out too quickly), better calibrate it through the engineering menu (#6484##). Completely shutting down increases the risk of accidental taps during calls. To deactivate the sensor, go to Settings → Calls → Incoming calls and turn off the appropriate option.

Why does the sensor work when I just hold my phone in my hand?

This is a typical problem when using magnets or metal inserts, and it can also be a sensor contamination or incorrect calibration, try removing the case and rubbing the top of the screen with a lilaless cloth, and if the problem persists, calibrate it through the engineering menu.

Could a faulty proximity sensor affect other functions?

Yes, but indirectly. For example, if the sensor constantly gives false positives, the system may mistakenly lock the screen while watching videos or games. Some applications (for example, Google Assistant) use the sensor data to optimize voice input, but the main functions of the phone (calls, Internet, camera) its failure does not affect.

How to protect the proximity sensor from damage?

To extend the life of the sensor, follow simple rules: 📱 Use covers without metal elements in the upper part. 🚫 Avoid falling the phone with the screen down. 💧 Do not expose your phone to moisture. 🧼 Clean the top of the screen from dust and fat regularly.

Where can I replace the proximity sensor with the Redmi 9C?

Official service centers Xiaomi in Russia and CIS countries perform replacement of the proximity sensor under warranty (if the breakdown is not caused by mechanical damage: 🔧 Unofficial service centers (cheap, but without a guarantee). 🛒 Ordering parts on AliExpress and self-replacement (only for power users).Warning: When replacing the sensor, the display is often repainted, which increases the cost of repair.

Conclusion: Whether to repair a faulty sensor

The proximity sensor is a small but important detail that greatly improves the user experience. If it stopped working on your Redmi 9C, try the software solutions (reboot, reset, calibration) first. 80% of the time, the problem is solved without repair.

However, if the sensor is physically damaged (for example, after a fall or water hit), it will be inexpensive to replace it and take no more than an hour at the service center. Given that the Redmi 9C is a budget smartphone, repairs are usually justified: the cost of parts and work rarely exceeds 2,000 rubles, which is cheaper than buying a new phone.

If you use a phone without a case and often drop it, consider buying a protective glass with a cutout for the sensor - this will prolong the life of not only the sensor, but the entire display.