How to set up the proximity sensor on Xiaomi Redmi 4X: the complete guide

The proximity sensor problem on Xiaomi smartphones, especially on legendary models like the Redmi 4X, is one of the most common complaints users have: When the screen goes out prematurely or does not turn off during a conversation and you drop calls with your ear, familiar to many owners of budget devices. The proximity sensor is a tiny but critical component that provides comfort for communication and prevents accidental cheek pressing.

Owners of Xiaomi Redmi 4X often face software failures or sensor contamination leading to incorrect operation. Fortunately, in the vast majority of cases, the problem is solved by software calibration that can be performed independently without contacting the service center. In this article, we will discuss in detail all the methods of setting, from simple reboots to using the engineering menu.

Before you start to do complex manipulations, you need to understand the physical nature of the sensor. In the Redmi 4X, it's located at the top of the front panel, next to the speaker; Infrared emitter sends a signal that bounces off the object (your ear) and returns to the receiver; if the distance is less than a given threshold, the system blocks the touchscreen.

A common cause of failure is not hardware failure, but software conflict or banal pollution. Dust, finger grease or improperly pasted protective glass can distort the sensor readings. So before you start software setting, be sure to wipe the top of the screen with microfiber and make sure that the protective film does not cover the sensor area.

It's worth noting that the MIUI architecture on the Redmi 4X has its own sensor-based processing features, and sometimes standard system settings can't independently correct errors that have arisen over time, and that's where the developers have provided hidden diagnostic and calibration tools, which we'll look at later.

Diagnostics of the problem: testing the sensor

The first step before any setup is to make sure that the problem is in the sensor, not the software failure of the operating system itself or the Phone application. There is a built-in engineering test in the MIUI shell that allows you to check the sensor response in real time.

To start the diagnosis, open the Phone app and enter the special code ##6484##. This action will automatically trigger the CIT (Customer Information Test) menu. In the list that appears, find the item "Proximity sensor" or "Proximation Sensor." When you click on it, you will see a screen with numerical values and status.

Hold your hand to the top of the screen without touching it. If the sensor is working, the value should change from 5.0 (or Far) to 0.0 (or Near), and the screen may flash green or red. If there is no reaction or the value "jumps" without impact, calibration is required. If the test shows stable results, but the screen is behaving strangely in the calls, the problem may be in the software.

• 🔍 Check if the sensor is sealed with a thick protective glass with a black frame.
• 🧹 Clean the top of the display of dust and grease before testing.
• 📱 Make sure that the phone does not run background processes that block the sensor.
• 🔄 Restart the device if the test shows obvious read errors.

Standard calibration through the engineering menu

If the initial test found a deviation, you need to perform a calibration procedure, which is the most effective method for overwriting sensitivity thresholds in the device's memory. For the Redmi 4X, this process takes only a couple of minutes, but requires precise execution of instructions.

Go back to the CIT engineering menu using code ##6484## and select "Proximity sensor." In the window that opens, you'll see the Calibration button. Click on it. The system will ask you to remove all items from the top of the screen and press OK.

Once confirmed, the phone will begin the process of measuring the reference values, at which point absolutely nothing should cover the top of the smartphone, in a few seconds, a message will appear about the successful calibration, if the process is unsuccessful, try again, making sure that you are in a well-lit room and keep the phone straight.

It is important to understand that after successful calibration, the changes take effect immediately. However, if you used third-party launchers or themes, they can caching old sensor settings, in which case it is recommended to perform a full reboot of the device so that the system resets all temporary files and applies new sensitivity settings.

Use of the Phone Sensor app

In some cases, MIUI's built-in tools may not work properly because of bugs in a particular firmware version, and the specialized tools available in the Google Play Market come to the rescue. One of the most reliable tools is the Phoenix Sensor app, which allows for deep calibration.

Once you install the app, run it and find the Proximity section, where you'll be asked to do a series of actions: first close the sensor with your hand, then open it, and the app will record the minimum and maximum values and suggest that you save the new profile.

The advantage of third-party utilities is that they often have more flexible threshold settings. You can manually set the sensitivity if the automatic mode does not work. However, be careful: too high sensitivity can cause the screen to go out even with a slight wave of your hand in the air.

Remember that installing third-party software requires careful attention to permissions, the application will need access to sensors and possibly the right to change system settings, after completing the calibration through third-party software, it is also recommended to restart the smartphone to consolidate the result.

Call settings and sensor lock

Sometimes the problem is not the sensor itself, but the settings of the phone application or system. There are functions in MIUI that can conflict with the proximity sensor, and checking these settings is a mandatory step in comprehensive diagnostics.

Go to the call settings (usually the three points in the Phone app -> Settings). Find the incoming call section. There may be a pocket mode option. If it's on, the sensor is in high-speed mode, which sometimes causes false positives. Try turning this feature off and check it.

Also worth paying attention to is the Sensor Lock feature, which in some versions of MIUI allows you to temporarily turn off the sensor when calling, which can be convenient but often leads to confusion. Make sure this feature is not activated accidentally if you want the screen to go out when you lift it to your ear.

If the problem persists after the change of settings, try to clear the phone application data. Go to Settings → Apps → All Apps → Phone → Memory → Clear the data. This action will reset all call settings to factory, but will not delete your contacts.

Problems with protective films and covers

One of the most common but common causes of sensor failure on the Redmi 4X is accessories, and the design of this smartphone is that the sensor is very close to the edge of the speaker, and any thickening in this area can be fatal to the correct operation.

Black-framed protective glass (full glue) often has a sensor cutout that doesn't match the actual location of the sensor in the factory, and as a result, the IR beam bounces off the film itself, and the phone thinks it's constantly being brought to the ear, so the solution is to carefully cut the hole above the sensor or replace the glass with a better one.

⚠️ Attention: If you use a thick, high-sided shockproof case, it can also block the angle of view of the sensor. Remove the case and check the sensor. If the problem is gone, find a more suitable accessory.

And then over time, the adhesive base of the protective glass can become cloudy or swell in the area of the sensor, which may be visually invisible, but for the infrared beam, it becomes an impassable barrier. Regularly inspect the area around the speaker for sticker defects.

Hardware malfunctions and repairs

If all the software methods, calibration and replacement of accessories did not help, there is likely a hardware breakdown. In the Redmi 4X, the proximity sensor is part of the front camera plume or soldered directly to the board (depending on the revision), and its failure is not uncommon.

Signs of hardware failure include: constant burning of the notification indicator (if it is tied to the sensor), complete lack of reaction in the engineering test even after flashing, or physical damage to the speaker area (impact, fall, moisture).

Replacing the device will require disassembly. In the Redmi 4X, it's a process of medium complexity: you need to remove the back cover, unscrew a lot of screws, remove the battery and the metal frame. The sensor itself costs a penny, but the work of replacing it requires skills and tools.

• 💧 Moisture infestation is the main enemy of the sensor, causing oxidation of contacts.
• 🔨 The impacts can damage the sensor crystal or unstick it from the body.
• 🔌 Trail retreat – a frequent problem after falls, requires reconnection.
• 🏭 Factory marriage – rare but possible, especially on refurbished devices.

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If the sensor is dead completely, and there is no possibility to carry it into the service, you can use the Proximity application, which emulates the operation of the sensor through an accelerometer (shaking), but this is a temporary and uncomfortable solution.

The cost of repairs at the service center is usually low, as the component itself is cheap. However, if you do not have experience disassembling smartphones, it is better not to risk, as you can damage the plume of the display or battery if you sloppy open the case of the Redmi 4X.

Frequently Asked Questions (FAQ)

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In 90% of cases, the problem is solved by simply cleaning the top of the screen and recalibrating through the CIT engineering menu.