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

The proximity sensor in Xiaomi Redmi 9C smartphones is a small but critical element that is responsible for automatically turning off the screen during a phone conversation. Without it, you would constantly press your cheek on the sensor, activating random functions or even completing calls. However, many users do not even know about its existence - until it begins to fail, for example, the screen does not go out when you bring the phone to your ear, or vice versa, it turns off too early, interfering with call management.

In this article, we’ll look at all the ways to turn on and configure the proximity sensor on the Redmi 9C, including hidden developer settings, checking hardware health and solving typical problems. You’ll learn exactly where this feature is hidden in the menu, why it can be disabled by default, and what to do if the sensor stopped responding after the MIUI update.

Important: The Redmi 9C (M2006C3LG) has an infrared proximity sensor that sits at the top of the screen next to the front camera, and it depends not only on the software settings, but also on the cleanliness of the sensor, the integrity of the security glass, and even the case, and if you recently dropped your phone or installed a thick bumper, it could cause a problem.

Before settings, make sure that the problem is not mechanical damage. For example, a crack in the top of the display or contamination of the sensor (dust, greasy traces) can block its signal. First, simply wipe the area around the camera with a soft wipe - sometimes this is enough to return functionality.

Where is the proximity sensor in the settings of Xiaomi Redmi 9C

You can monitor the proximity sensor through standard MIUI settings, but the path to it is not always obvious. Unlike Xiaomi's flagship models, where this option is put on a separate menu, on the budget Redmi 9C it is hidden deeper.

1. Open the Settings app (the gear icon on the home screen).

2. Go to the section "System and device» → «Additional" (in some versions) MIUI This item may be called “Extended settings»).

3. Find the submenu "Special features" (or "Useability").

4. Scroll down to the Physical Buttons block and select Automatic Screen Shutdown.

Here you'll see the Approximation Sensor switch. If it's active (the slider is shifted to the right), the function works. However, on Redmi 9C, this setting may be hidden by default, in which case you'll need to activate Developer Mode.

How to turn on the proximity sensor through the developer mode

If the standard path doesn't work, or if the option isn't on the menu, you'll have to use Developer Options, which is hidden in MIUI by default, but it's easy to activate:

1. Open "Settings" → "About the phone."

2. Find the line "Version" MIUI» And then you tap it 7 times in a row, and then you'll see a notification saying, "You've become a developer!».

3. Go back to the main Settings menu and find the new section “Additional” → “Developer Options” (or “Developers”).

Inside this menu, scroll down to the input box. Here you're interested in two things:

• 🔹 «Turn off the screen when approaching" - the main sensor switch.
• 🔹 «Show the presses" - optionally, will help to visually track the sensor response (circles will appear in touching places).

If the “Switch off screen when approaching” switch is missing, this may mean:

• 📱 Your version. MIUI Very outdated (update the firmware through Settings) → Updating the system).
• 🛠️ Sensor physically damaged (requires diagnostics in the service).
• 🔧 There was a software failure (will help reset settings to factory).

Open "Developer Options" |Enable "Switch off screen when approaching" |Test screen response during call |Test the cleanness of the sensor area (top frame) |Update MIUI to the latest version-->

Why the proximity sensor doesn't work on Redmi 9C: top-up-5 cause

If the sensor doesn't respond after all the manipulations, the problem may lie in one of the following factors: We have collected the most common causes of proximity sensor failure on Xiaomi Redmi 9C, ranked by the frequency of calls to service centers:

Especially when you upgrade MIUI to 12.5 and higher, Redmi 9C users complain that when you update, the screen stops dimming during calls, even though the settings are all inclusive, in which case you can roll back to the previous firmware version or reset to factory settings.

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If the sensor started to crash after installing custom firmware (like LineageOS), try returning the official MIUI via Fastboot.Unofficial builds are often not optimized for Xiaomi's budget models.

How to check the proximity sensor for serviceability without applications

Before you carry your phone for repair, you can test the sensor yourself using a hidden engineering menu or standard MIUI tools.

Method 1: Using the USSD code

1. Open the Phone app and enter the combination: ##6484###.

2. The "Manual Test" menu will appear on the screen.

3. Select the item "Proximity Sensor" (proximity sensor).

4. Cover the top of the phone with your hand -- if the sensor is working, the screen will change color to green (or "PASS" will appear).

Method 2: Through the Developer's Parameters

1. Activate “Show Clicks” in the Developer menu (see section above).

2.Call another phone and hold the Redmi 9C to your ear.

3 If the sensor is working, the screen will go out, and when you pull the phone, it will turn back on. If not, check the settings or contact the service.

Software solutions: resetting settings and calibration of the sensor

If the hardware checks didn't show any problems, but the sensor still doesn't work, try software recovery methods. Let's start with the safest one: calibration.

1. Install the Sensor Test or CPU-Z app from Google Play.

2. Run the proximity sensor test.

3. If the application offers “Calibration” – perform it (usually you need to cover the sensor with your hand and wait 10 seconds).

If calibration does not help, the next step is to reset the settings to factory:

⚠️ Warning: Reset will delete all data from your phone, including photos, contacts and apps. pre-backup through Settings → System and device → Backup.

Resetting instructions:

1. Go to Settings → System and Device → Settings Reset.

2. Select “Erase all data” (may be called “Hard reset”).

3. Confirm the action and wait for the reboot.

Once reset, the proximity sensor should be operating normally, and if the problem persists, it's a 100% hardware fault, and you can't do without repairs.

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Resetting helps in 70% of the cases of software failures of the proximity sensor, and if after this procedure the problem persists, either a physical defect of the sensor or damage to the motherboard plume is to blame.

What to do if the proximity sensor is not working properly (extinguishes too soon or later)

Sometimes the sensor turns on, but it doesn't behave properly: the screen goes off too quickly (before it's even touched to the ear) or doesn't respond at all, which can be due to incorrect sensitivity settings or conflict with the MIUI shell.

Problem 1: The screen goes out too soon

• 📵 Check if the cover or the protective film is disturbing, and try to remove them and test the sensor again.
• 🔧 In Developer Settings, find the item “Approximation Sensitivity” (if any) and reduce the value.
• 🔄 Update. MIUI until the latest version - in new builds often fix bugs with sensors.

Problem 2: The screen doesn't go out at all

• 🧹 Wipe the top bezel of the phone – it’s possible the sensor is blocked by dirt.
• 🔧 Include in the Developer Settings the option “Switch off the screen when approaching” (if it is disabled).
• 📱 Check if gesture control apps (such as EasyTouch) are installed that may conflict with the sensor.

If neither of these methods worked, there are two options:

1. Reverse the firmware to the previous version of MIUI (if the failures began after the update).
2. Contact the service center for the diagnostics of the hardware.

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On the Redmi 9C, the proximity sensor often conflicts with the "Raise to Activate" function (includes in Settings → Screen → Lock and Protection).

Hardware repair: when without service can not do

If all software methods are exhausted and the proximity sensor is still down, the problem is a physical malfunction.

• 💥 The phone fell or was subjected to severe vibration (for example, in a car without mounting).
• 💧 Moisture fell under the body (even if everything is dry, corrosion could damage the contacts).
• 🔧 The sensor does not respond to any tests, including the engineering menu.
• 📱 After disassembling the phone (for example, to replace the battery), the function is lost.

The service will offer you the following types of repairs:

⚠️ Attention: On Redmi 9C The proximity sensor often fails after a failed display replacement, because it's glued to the camera module, and if you're not neatly dismantled, it's easy to damage it. If you've recently changed the screen, let the wizard know.

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