Approximation Sensor on Xiaomi Redmi: how to turn on, configure and check

The proximity sensor in Xiaomi Redmi smartphones is a small but critical component that automatically shuts down the screen during a phone call. When you bring the device to your ear, the sensor registers the obstacle and extinguishes the backlight, preventing accidental pressing and saving battery power, but many users face the problem when this sensor suddenly stops working — the screen does not go out when you call, or, conversely, it turns off for no reason.

In this article, we will learn how to properly turn on the proximity sensor on Xiaomi Redmi, where to find its settings in MIUI, and also to diagnose possible malfunctions. It is important to understand that the problem can lie not only in software failures, but also in physical damage to the sensor — for example, after a phone falls or moisture hits. We will look at all scenarios, from basic activation to complex cases where you need to intervene in system files.

If your Redmi Note 10, Redmi 9 or other model is not behaving properly during calls, don’t rush to bring your phone to the service. 80% of the time, you can solve the problem yourself in 5-10 minutes, following our instructions.

What is a proximity sensor and why you need it

The proximity sensor is an infrared sensor located at the top of the smartphone screen (usually next to the speaker or front camera), its main task is to detect when you hold the phone to your ear while you are talking. Once the sensor detects an obstacle at a distance of 2-5 cm, it sends a signal to the system, and the screen goes out.

• 📵 Accidental tapping of the cheek or ear (for example, completing a call or activating a hands-free communication).
• 🔋 Unnecessary battery consumption – screen lighting consumes a significant portion of the energy.
• 👁️ Discomfort for the eyes if the screen continues to glow near the face.

On Xiaomi Redmi smartphones, the proximity sensor is paired with a light sensor that regulates the brightness of the screen. Both sensors are often combined in one module, so if one is damaged, the second one can suffer, for example, if after the phone falls, the screen stopped automatically extinguishing during calls and stopped adjusting the brightness, most likely the entire sensor module is damaged.

In modern Redmi models (such as Redmi Note 12 or Redmi K50), the proximity sensor is also used to:

• 🎧 Automatic on/off screen when using wireless headphones (in some firmware).
• 📱 Optimizing gestures – for example, blocking random swipes in your pocket.
• 🔒 Security improvements: Some banking applications use a sensor to confirm a live user.

Where is the proximity sensor on Xiaomi Redmi

The location of the sensor depends on the model of the smartphone, but in 90% of cases it can be found at the top of the screen, next to the front camera or speaker.

On some models (like the Redmi Note 12 Pro+), the proximity sensor is integrated into the screen and not visible to the outside. To detect it, you can use a sensor test through an engineering menu or an application like the CPU-Z. You can also shine a flashlight at the top of the screen at an angle - sometimes the sensor appears as a weak spot.

If you are not sure where exactly the sensor is on your model, do the following:

1. Open the Phone app and type ##6484## (sensor test code for the device) MIUI).
2. In the menu that appears, select Proximity Sensor.
3. Close the sensor with your finger – if it works, the screen should change color or show a value of 0 (obstacle detected).

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If the code ##6484## doesn't work, try ##4636## → Testing → Sensors.

How to turn on the proximity sensor in the MIUI settings

In most cases, the proximity sensor on Xiaomi Redmi is turned on by default, but sometimes its operation can be blocked due to:

• 🔄 Resetting settings to factory.
• 📱 Updates MIUI (Especially when switching to a new version of Android).
• 🛠️ Manual shutdown in the engineering menu.
• 🎭 Use of custom firmware or Magisk modules.

To check and turn on the sensor, follow the following steps:

1. Open Settings → Applications → Application Management.
2. Click on the three dots in the top right corner and select Special Accesses.
3. Scroll down and find the Other Permissions → Change System Settings section.
4. Make sure that the phone app (com.android.dialer) is allowed access to change system settings. If not, turn it on.

If the sensor still doesn’t work, try turning it on through the engineering menu:

1. Open the Phone app and enter the code ##3646633## (or #4636## for newer versions of MIUI).
2. Go to the Hardware Testing → Sensor section.
3. Find the Proximity Sensor string and click on it.
4. Make sure that the Enabled option is set in Yes. If not, turn it on.

Go to Settings → About Phone → MIUI Version (click 5 times to unlock the engineering menu)|

Enter the code ##3646633## and check the Sensor| section.

Make sure that the phone settings allow access to system settings |

Check the physical cleanliness of the sensor (whether there is dirt or protective film)-->

If after all the manipulations the sensor still does not respond, the problem may be:

• 🧹 Sensor contamination (dust, fat, residues of protective film).
• 💥 Damage after falling (cracks on sensor module).
• 🔄 Firmware failure (especially after unofficial updates).

Checking the operability of the proximity sensor

Before you commit a hardware malfunction, make sure that the sensor is not working. There are several reliable methods for this:

Method 1: Testing with USSD code

The fastest way to check the sensor is to use hidden MIUI codes:

1. Open the Phone app.
2. Enter ##6484## (for older versions of MIUI) or ##4636## (for newer versions).
3. Choose the Sensor Test → Proximity Sensor.
4. Close the sensor with your finger. If it is working, the screen should change color to green or show a value of 0 (obstacle detected). When you remove the finger, the value should return to 1 or 5 (no obstacle).

Method 2: Diagnostic applications

If USSD-The codes are not working, install one of these applications:

• 📊 CPU-Z (sensors).
• 🔍 Phone Doctor Plus (Test of Sensors).
• 🛠️ Sensor Test (from Innovative Apps).

In these applications, the proximity sensor is usually labeled as the Proximity Sensor. Cover it with your finger, and the graph should respond to changes.

Method 3: Manually check during a call

The most obvious test is to call another phone and check the behavior of the screen:

1. Make a call (you can make it to your second number).
2. As soon as the caller responds, hold the phone to your ear.
3. The screen should go out instantly (within 0.5-1 seconds).
4. Remove the phone from your ear, the screen should light up again.

If the screen doesn't go out or doesn't turn on after the phone is removed, the problem is confirmed, but before you bring the phone to the service, try the software solutions described below.

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If the sensor does not respond to any of the tests, but at the same time in the engineering menu is displayed as "Enabled", most likely, the problem is hardware - the sensor itself or its plume is damaged.

Why the proximity sensor doesn’t work and how to fix it

If the proximity sensor on your Xiaomi Redmi has stopped functioning, the reasons can be divided into three categories: software, hardware and external.

1. Programmatic failures

The most common cause of a sensor that's broken is a firmware failure or application conflict.

• 🔄 Sometimes a bug is caused by a temporary system failure.
• 📱 Update. MIUI. Go to Settings. → The phone. → Update the system and check for updates.
• 🧹 Clear the cache of the Phone application: Open Settings → Annexes → Application management. Find the phone (com.android.dialer). Click Clear cache and Clear data (Warning: this will reset your call history!).

Reset the network settings

→ SIM-maps and mobile networks → Network reset

Hardware malfunctions

If the software methods did not help, the problem may be:

• 💥 Damage to the sensor after a fall or impact.
• 💧 Moisture infestation (even if the phone didn’t sink, condensation could damage contacts).
• 🔌 Disconnection of the plume (relevant after self-disassembly of the phone).