Disabling the proximity sensor on Xiaomi 9A: causes, risks and step-by-step instructions

The proximity sensor in the Xiaomi 9A is a small but important element that automatically shuts down the screen during phone calls, but it sometimes fails: the screen does not go off when the device is brought to the ear or, conversely, turns off at the wrong time, in which cases users are looking for ways to temporarily or completely deactivate the sensor.

In this article, we will discuss three official and informal methods for disabling the proximity sensor on the Xiaomi 9A, including MIUI settings, engineering menus and ADB commands. You will also learn what problems can occur after deactivation and how to avoid them. Importantly, some methods require superuser rights (root) or connection to a PC – we will describe each step in detail.

Why does the proximity sensor interfere?

The main purpose of the sensor is to save battery power and prevent accidental taps during a call. However, in practice, users of the Xiaomi 9A face typical problems:

• 📵 The screen does not go out when you bring the phone to the ear, which causes the ear to accidentally press buttons (for example, turns off the microphone or speaker keys).
• 🔄 False positives: The sensor turns off the screen when you just hold the phone in your hand or put it on the table.
• 🛠️ Hardware malfunctions: after falling or getting moisture, the sensor begins to work incorrectly.
• 🎧 Headset conflict: when connecting headphones, the sensor continues to block the screen.

If you notice at least one of these issues, try restarting your phone first or clearing the sensor cache through Settings → Apps → App Management → Three Dots → Show System → Sensors. If that doesn’t work, read on.

Method 1: Disconnect via MIUI settings (without root)

The easiest and safest method is to use the built-in MIUI features. Unfortunately, there is no direct option in the standard Xiaomi 9A settings to disable the proximity sensor, but you can get around this restriction through the developer mode.

Instructions:

1. Activate Developer Mode: Go to Settings → About Phone. Tap 7 times on MIUI Version (you will be notified "You're a developer!").

Settings

Additional → For Developers

USB debugging

Connect the phone to the PC and confirm the debugging permission.

Win + R → cmd

adb shell settings put global proximity_delay 2500

This command increases the sensor’s latency to 2.5 seconds, effectively rendering it useless.

⚠️ Attention: After the phone restarts, the settings may reset. To fix the changes, use the command:

adb shell settings put global proximity_delay_permanent 1

Method 2: Engineering menu (codes and settings)

All Xiaomi smartphones have a hidden engineering menu where you can test and disable the sensors. For Xiaomi 9A, two login methods are suitable:

• 📞 Open the Phone app and type ##6484## (sensor test) or #4636## (general information).
• 🔧 Through the application: Install the utility from the Play Market MTK Engineering Mode (if you have a MediaTek processor) or Qualcomm EngineerMode.

On the engineering menu:

1. Select Hardware Testing → Sensor.
2. Find the Proximity Sensor (approximation sensor).
3. Select Disable or Turn Off.
4. Save the changes and restart the phone.

⚠️ Warning: Some items on the engineering menu may cause you to reset or damage your firmware. Do not change settings unless you are sure they are intended!

Method 3: Disconnecting through root access (for experienced)

If the first two methods don't work, the radical thing is to turn off the sensor at the system level.

• 🔓 Root rights (for example, through Magisk or SuperSU).
• 📱 Root Explorer (Root Explorer, Solid Explorer).
• 💾 Backup of important data (risk of system damage!).

Instructions:

1. Open the file manager and follow the path: /system/usr/idc/
2. Find the proximity.idc file (or similar to the sensor name).
3. Rename it to proximity.idc.bak or delete it.
4. Reboot the phone.

💡 Useful tip: Before deleting system files, make a backup copy of them to SD-If the phone stops responding to calls after the changes, return the file to its place.

What happens if you turn off the proximity sensor?

Deactivation of the sensor solves the problem of false positives, but introduces new inconveniences:

• 📞 The screen will not go out during the call, which will lead to accidental pressing of the cheek or ear.
• 🔋 Increased battery consumption as the screen stays on longer.
• 🎤 Risk of turning off the microphone or switching to speakerphone when touching the screen.
• 🛡️ Fraudster vulnerability: If the phone is screened up, the caller can see your notifications.

Critical information: On some Xiaomi 9A firmware, disabling the proximity sensor causes the Lift to wake function to fail. If this gesture is important to you, check its performance after the changes.

💡

Turn off the proximity sensor only if it really interferes! In most cases, the problem can be solved by calibrating or replacing the protective glass (it can block the sensor signal).

Alternative solutions: calibration and replacement of the sensor

Before you radically turn off the sensor, try less risky methods:

• 🔄 Sensor calibration: Dial ##6484## in your phone. Select Proximity Sensor. Follow the instructions on the screen (usually close the sensor with your hand and wait for the signal).

Replacement of protective glass:

Resetting:

Settings → System → Resetting settings → Reset all settings

If the sensor is physically damaged (for example, after a fall or moisture), it will cost 500-1,500 rubles to replace it at the service center. For the Xiaomi 9A, this is cheaper than risking the phone’s performance if it fails to shut down.

Frequent Mistakes and How to Avoid Them

Users often make the following mistakes when trying to disable the sensor:

⚠️ Warning: Never use commands ADB Or changes to system files downloaded from unverified sources, which could lead to malware installation or firmware damage. All the commands in this article are safe, but type them manually.

• 🚫 Use of utilities "one click": Applications like Proximity Sensor Fix often require root and contain advertising software.
• 🔌 Disabling the sensor through build.prop: Editing this file without knowing can make the phone inoperable. Don't add lines like ro.proximity.delay.=2500 without backup!
• 🔄 Ignoring reboot: After changes to the engineering menu or ADB Always restart your phone or the settings will not apply.