How to turn on the proximity sensor on Xiaomi Redmi 9: detailed instructions

The proximity sensor in Xiaomi Redmi 9 is a small but important element that is responsible for automatically turning off the screen during a phone conversation. When you hold your smartphone to your ear, the sensor detects the obstacle and extinguishes the display, preventing accidental pressing and saving battery power. However, sometimes users are faced with the sensor stops working or is turned off by default. In this article, we will discuss how to properly activate it, check for serviceability and fix possible problems.

Redmi 9 owners often confuse proximity sensor issues with software failures or mechanical damage. For example, if the screen doesn't go out when you call, it could be due to both a feature that's turned off in the settings, and a sensor contamination or plume damage, and we'll look at everything from basic activation to hardware malfunction diagnosis.

It is important to understand that the proximity sensor setting is closely related to firmware. MIUI. The menu shells may vary slightly from one version to the other, but the overall algorithm remains the same. If you've recently upgraded your smartphone or reset it to factory settings, check the settings again, they may have gone wrong.

What is a proximity sensor and why you need it

The proximity sensor is an infrared sensor located at the top of the Xiaomi Redmi 9 screen, next to the front camera, and its main task is to determine the distance between the smartphone and an object (for example, your ear while you are talking), when you hold the phone to your head, the sensor sends a signal to the system, and the screen automatically turns off.

• 📱 Accidental taps on the screen with the cheek or ear
• 🔋 Unnecessary battery consumption (screen illumination consumes a lot of energy)
• 🔊 Sound problems (for example, when the screen remains active and the microphone switches to speakerphone)

Redmi 9 uses an infrared proximity sensor that works by reflecting the beam, and it emits a signal that is invisible to the human eye and analyzes its return, and if the beam is bouncing off a nearby object (like your hand), the system recognizes that the phone is near your face.

Note that the proximity sensor is also used in some applications, such as Google Assistant or Xiaomi. AI It can be used to activate the voice assistant when you hold your phone to your ear, and some games and services (such as TikTok or YouTube) use the sensor to optimize energy consumption while watching videos.

Where is the proximity sensor on Xiaomi Redmi 9

On the Xiaomi Redmi 9, the proximity sensor is located at the top of the front panel, to the right of the front camera (if you look at the screen), visually difficult to see, because it is hidden under the protective glass and has no visible holes, but if you look closely, you can see a small darkened spot about 2-3 mm in size.

To determine the location of the sensor, follow the following steps:

1. Turn on the flashlight on another smartphone.
2. Hold the Redmi 9 screen up and shine the flashlight at an angle to the top of the display.
3. The approach sensor will look like a small dark spot to the right of the camera (on some models, on the left).

If you can't find the sensor visually, use the test mode.

1. Open the Phone app.
2. Enter the combination ##6484## (some firmware may not work).
3. If the code worked, you’ll see the Manual Test menu, where you can check all sensors, including approximations.

Redmi 9 also has a light sensor, which is often confused with a proximity sensor, which is located next to it, but is responsible for automatically adjusting the brightness of the screen, and these two sensors operate independently of each other, although they are in the same module.

Step-by-step: how to turn on the proximity sensor

If the proximity sensor on your Xiaomi Redmi 9 is disabled, it can be activated through the system settings. MIUI There's no separate switch for this sensor, it's controlled through call settings:

1. Open the Settings app (the gear icon on the home screen).
2. Go to the Appendix section → Application management.
3. Find and select the phone in the list.
4. Slip on the Permission.
5. Make sure the Sensor resolution is on (the slider must be active).
6. Go back to the basic settings and select System Applications → Calls.
7. Activate the option Automatically turn off the screen during the call (the name may vary slightly depending on the version). MIUI).

If the sensor still does not work after these actions, check the following points:

• 📲 Make sure that there is no protective film or glass on the phone that covers the sensor, even a thin coating can block the infrared signal.
• 🔄 Restart your smartphone – sometimes software failures interfere with the correct operation of the sensor.
• 🛠️ Update your firmware to the latest version (path: Settings) → The phone. → Updating the system).

Remove the cover or film from the top of the screen|

Check if there is any physical damage near the front camera|

Update MIUI to current version|

Reboot your smartphone-->

If the sensor is still not functioning, the problem may be in the hardware, in which case we recommend contacting the Xiaomi service center for diagnostics. However, before you try to reset the settings to the factory (don’t forget to back up the data!).

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If the proximity sensor is triggered too late or too early, try calibrating it using the engineering menu. To do this, type the code ##6484## and select Proximity Sensor (if available).

How to check the operability of the sensor of approach

To make sure that the proximity sensor on Redmi 9 is working correctly, there are several methods you can use, and the easiest way is to call another phone and check if the screen goes out when you touch your ear, but there are more accurate tests.

Method 1: Use of engineering menus

The engineering menu provides detailed information on the status of all sensors.

1. Open the Phone app.
2. Enter the combination ##4636##.
3. In the menu that opens, select Sensor Test Information (or Sensor Test).
4. Find the Proximity Sensor line.
5. Raise your hand to the top of the screen – the value should change from 5.00 (no obstacle) to 0.00 (object detected).

If the values do not change or an error is displayed, this indicates a sensor malfunction or firmware problems.

Method 2: Applications for testing

Google Play has tools that help diagnose sensors, for example, CPU-Z Or Sensor Test. Install one of these and follow the instructions:

1. Open the app and find the Sensors section.
2. Select Proximity Sensor.
3. Raise your hand to the top of the screen – the graph should show the change in status.

If the app does not detect the sensor or shows static values, this can mean:

• 🔧 Software failure (solved by rebooting or resetting settings).
• 🛠️ Hardware breakdown (required repairs).
• 📱 Lack of drivers (relevant after unofficial firmware).

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If the proximity sensor doesn't respond to any of the tests, but the other sensors (gyroscope, accelerometer) are working normally, the problem is probably hardware, 90% of the time it's damage to the plume or the sensor itself.

Frequent problems and their solutions

Xiaomi Redmi 9 users often encounter typical proximity sensor problems, and let’s look at the most common ones and how to fix them.

One of the most common causes of sensor malfunction is pollution, and dust, greasy finger marks, or residues of adhesive from a protective film can block the infrared signal, so that the sensor can be cleaned.

1. Turn off your smartphone.
2. Take a soft, hairless fabric (for example, for glasses) and slightly wipe the top of the screen.
3. If you have a lot of pollution, use an alcohol napkin (no more than 70% alcohol!).
4. Don’t press hard – the sensor is located under the glass and may be damaged.

If the problem occurs after the update MIUI, Try to roll back on the previous firmware version or wait for a patch from the developers. Sometimes bugs in new builds affect the performance of sensors.

⚠️ Note: Do not use abrasive materials (such as paper wipes or rough fabrics) to clean the sensor, they may scratch the protective glass and damage the sensor, and avoid liquid entering the speaker or microphone located nearby.

Additional settings and optimization

The Xiaomi Redmi 9 has several hidden features that allow you to fine-tune the approach sensor, for example, you can change the sensitivity of the sensor or turn it off for specific applications.

Change in sensor sensitivity

If the sensor is triggered too early or late, it can be calibrated.

1. Enter the phone code ##6484##.
2. Select Proximity Sensor (if you have one).
3. Follow the instructions on the screen for calibration.

If the engineering menu isn't available, try using the Sensor Calibration app from Google Play, which lets you manually adjust the trigger threshold.

Disabling the sensor for individual applications

Sometimes the proximity sensor interferes with certain programs (such as games or instant messengers) to turn it off selectively:

1. Install the Tasker or MacroDroid app.
2. Create a new task with the condition Application is running (specify the desired application).
3. Add the action to Disable the proximity sensor (root access may be required).

Be careful: Disabling the sensor in some applications (such as the phone) can cause inconvenience during calls.

Saving battery with sensor

The proximity sensor indirectly affects battery consumption, and if it doesn't work properly, the screen can stay on during calls, which leads to additional power consumption, to optimize the operation:

• 🔋 Enable Charge Saving Mode in Battery Settings.
• 📵 Reduce the waiting time for automatic screen shutdown (path: Settings) → Display. → Sleeping mode).
• 🔄 Check the sensor regularly for contamination.

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If you make frequent calls with headphones, you can turn off the proximity sensor completely. To do this, deactivate the option Automatically Turn off the screen in the Call settings. This will save system resources.

What to do if the proximity sensor is not working

If none of these methods worked, and the proximity sensor on Redmi 9 is still not working, the reasons could be more serious.

Programmatic failures

Sometimes problems with the sensor arise due to:

• 📱 Unofficial firmware (such as LineageOS or Pixel Experience).
• 🔄 Conflicts after update MIUI.
• 🛠️ Viruses or malicious applications.

Decisions:

1. Perform a reset to factory settings (Settings → About Phone → Reset settings).
2. Refuse the smartphone to the official version MIUI via Mi Flash Tool.
3. Check your phone for viruses using Malwarebytes or Dr.Web.

Hardware malfunctions

If the software methods didn't work, the problem is probably the hardware.

• 🔌 Damage to the plume connecting the sensor to the motherboard.
• 💧 Getting moisture in the upper part of the smartphone.
• 🛠️ Mechanical damage to the sensor (for example, after a fall).

In these cases, self-repair is not recommended. Contact an authorized Xiaomi service center or a trusted wizard. The average cost of replacing the proximity sensor with a Redmi 9 is 800-1500 rubles (depending on the region and service).

⚠️ Warning: If you notice that the sensor stopped working after a smartphone drop or moisture hit, do not try to disassemble the device yourself. This can lead to even more serious damage, such as a failure of the display or motherboard.

Provisional decision

If repairs are delayed and the sensor is not working, you can use temporary measures:

• 📱 Use a headset or headphones to make calls – in this case, the screen will not go out.
• 🔄 Turn on Do Not Disturb During Conversations to Block Accidental Pressing.
• 🛠️ Install an application to force the screen to turn off (e.g. Proximity Screen Off).

Remember that these methods do not replace a full-fledged repair, but will help reduce discomfort before visiting the service center.

FAQ: Frequently Asked Questions