The proximity sensor problem on Redmi and Xiaomi smartphones is one of the most talked-about issues among users, and the Note 8 Pro is no exception here. Often, owners are faced with a situation where the screen goes out too early or does not turn off at all during a conversation, which leads to accidental cheekstrokes. The proximity sensor is a tiny sensor located at the top of the display that responds to objects in close proximity to it.
In most cases, MIUI software regulates the operation of this component itself, but sometimes manual intervention is required to work correctly, this may be due to a pasted protective film, a software failure or calibration features after a system update. In this article, we will discuss in detail how to activate hidden functions, conduct accurate calibration and eliminate typical errors that interfere with comfortable communication.
It is worth noting that ignoring the problems with this sensor can lead to significant discomfort in the operation of the device. If the screen does not go out during a conversation, you risk accidentally hanging up the phone, turning on speakerphone or running an unnecessary application. Below are proven methods that will help return the functionality of your Redmi Note 8 Pro in the shortest possible time without the need to contact a service center.
Check the performance of the sensor through the engineering menu
Before you try to fix or turn on something, you need to make sure that the hardware module itself is functional and determined by the system. There is a built-in diagnostic tool in the MIUI shell that can be accessed through a special code in the Phone application.
To start, open the standard caller and enter the universal code ##6484##. If you did everything right, the CIT menu will open, containing a list of all the components tested on the smartphone. Find the item "Proximity Sensor" or "Approximation Sensor" in the list. When you click on it, you will see a screen with numerical values that change if you close the top of the screen with your hand.
If the values change (for example, from 5.0 to 0.0), then the sensor is physically working properly, and the problem lies in the software settings or calibration. In the case of no reaction, it is worth checking whether the sensor is covered with a protective glass or case. Also make sure that there is no strong contamination at the top of the screen.
- 📱 Enter the code ##6484## in the Engineering Menu Call App.
- 🔍 Find the Proximity Sensor test in the list and click on it to check it out.
- ✋ Close the upper part of the screen with your palm and watch for changes in the readings on the display.
- 🧹 Wipe the front camera area and speaker if the sensor is not responsive to movement.
Activation of the function "approximation sensor" in call settings
Often, users look for complex solutions, forgetting about the basic system settings. The standard Xiaomi call app has a separate switch that directly controls the behavior of the screen during a conversation. If it is turned off, the screen will burn constantly, regardless of whether you hold the phone to your ear or not.
To check this setting, open the Phone app and click on the three dots or menu button in the upper right corner. Select Settings, then go to Incoming Calls. This is where the switch is located. Make sure that the Upcoming Sensor is set to active status.
In some versions of MIUI, this may be called a little differently, such as, "Switch off the screen when you touch your ear." The logic remains the same: activating this feature allows the system to rely on sensor readings to control the display backlight. If the switch is already on, but the problem persists, move on to the next sections of the instructions.
⚠️ Note: If the switch in call settings is gray (inactive) and cannot be pressed, this may indicate a conflict with installed call recording apps or third-party calls.
It's also worth mentioning that once you upgrade the operating system, you can reset to factory values, so after every major Android or MIUI update, it makes sense to manually recheck that setting, which will take just a minute, but will save you a lot of inconvenience in the future.
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If the standard call settings menu does not open or crashes, try clearing the Phone app cache through the Applications menu in the general system settings.
Calibration of the proximity sensor on the Redmi Note 8 Pro
The most effective way to solve the problem of black screens or their constant burning is calibration, a process in which the system remembers the minimum and maximum light values considered by the sensor. For the Redmi Note 8 Pro, this procedure often becomes necessary after replacing the display or glass.
Go back to the CIT engineering menu we opened earlier with code ##6484##. Find the "Proximity Sensor" item. In the window that opens, you'll see two buttons: "Calibrate" and "Get Values." Make sure there's nothing in front of the screen before you start, and then press the calibration button.
The system will ask you to close the sensor (usually a message that says "Put phone in pocket" or similar) and cover the top of the screen with your palm tightly, without gaps, and wait for the vibration or the beep. Then remove your hand. If the calibration is successful, you will see a message "Pass" or "Success".
☑️ Checklist of successful calibration
It is important to do this in good light, but not in direct sunlight, which can blind the sensor. If after a few attempts the system produces a Fail error, try restarting the device and repeating the process. In rare cases, you need to repeat the calibration cycle 3-5 times in a row to stabilize the readings.
Using engineering code to reset sensor settings
There is an alternative and deeper method of resetting that is available through another engineering menu, which often helps when the standard calibration in the CIT menu fails, and it allows you to reset the accumulated errors in the operation of the sensor module.
Type in dialer code ##64663##. This code opens an extended hardware testing menu. Find the "Proximity Sensor" list. Unlike the previous method, you may need to execute a reset command. Press the "Calibration" or "Reset" button if it's available in your firmware version.
Once the reset is complete, it is imperative to restart the smartphone. Without a reboot, the new parameters may not take effect, a method that is particularly effective for devices that have been flashed or unlocked by the bootloader.
| Method | Access code | Difficulty | Efficiency |
|---|---|---|---|
| Standard CIT menu | ##6484## | Low. | Tall. |
| Extended test | ##64663## | Medium | Medium |
| Engineer Mode Application | Through APK installation | Tall. | Maximum |
| Call settings | Phone menu | Minimum | Basic |
Remember that access to the engineering menus may be blocked by the carrier or manufacturer in some regions. If the codes do not work, try using third-party utility to activate the engineering mode available in the official Google Play store.
What do I do if the codes don't work?
Third-party applications for sensor control
When Xiaomi's built-in tools are not flexible enough, specialized apps come to the rescue from the app store. One of the most popular and proven tools is Proximity Sensor Reset & Test, which allows you to fine-tune your trigger thresholds more carefully.
Once you install the app, run the test. It will show you a real-time graph of how dramatically the reading changes and if there is a "shaking" of the values that can lead to false positives. In the application settings, you can set a threshold at which the screen will go out.
Another useful feature of these applications is the ability to programmatically disable the sensor, which can be useful if the sensor is physically damaged and you want to use the phone without permanently locking the screen while you're talking, but it's a temporary solution, and it's best to address the root of the problem.
- 📥 Download a proven sensor application from a reliable source.
- 📊 Test and analyze the schedule of changes in values.
- ⚙️ Change the sensitivity threshold if the standard values do not fit.
- 🔄 Use the "Reset" function to reset accumulated driver errors.
Using third-party software requires care, make sure the application has the necessary permissions to work with the system, do not install dubious utilities with a lot of advertising, as they can cause conflicts in the system.
Typical errors and physical maintenance
The Redmi Note 8 Pro has a sensor built into the body under the screen or next to the speaker, and low-quality security glass often has opaque perforation or simply seals the area, making it impossible for the sensor to work.
If you've recently changed a glass or a display, the wizard might have forgotten to calibrate the new module or install it incorrectly, and it's also worth checking if moisture has entered the case, and even a microscopic drop of condensate in the sensor area can distort its readings, making it seem like the phone is constantly in the ear.
⚠️ Warning: Never use sharp objects to clean the sensor area.You may damage the sensor element or scratch the coating, permanently impairing the quality of light transmission.
In some cases, the problem is solved by simply removing the case. Tight silicone bumpers with high sides can mechanically close the sensitivity zone. Try removing the case and checking the sensor in a "clean" form. If the problem is gone, you should replace the accessory with a more compatible one with your model.
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In 80% of cases, the problem is solved by removing poor-quality protective glass or recalibrating through the CIT engineering menu.
If none of these things worked, maybe the sensor plume itself or the circuit board contact failed, and in this situation, the software methods are powerless, and you'll need to visit a service center to replace the component, but this is rarely the case, and software customization usually brings the device back to life.