Setting up screen lock during a call on Xiaomi Redmi 9T: the full guide

Xiaomi Redmi 9T smartphones feature automatic screen lock during phone conversations, which is designed to prevent accidental clicking of the cheek or ear. However, for many users this becomes a real problem: you can not take advantage of additional features during a call, turn on speakerphone or switch to another contact. Fortunately, the manufacturer has provided several ways to adjust this setting.

In this article, we will take a look at all the available ways to disable or adjust the lock screen on the Redmi 9T, from standard MIUI settings to hidden features of the engineering menu. You will learn how to fully deactivate the function, adjust the lock delay or use alternative solutions for comfortable communication.

Why the screen is locked during a call and why it is necessary

The automatic screen locking feature (proximal sensor) has been introduced into smartphones to address three key issues:

• 📱 Preventing accidental taps – when you put your phone to your ear, the cheek or earlobe can activate the touch screen, leading to the call being completed, hands-free turned on, or other unwanted actions.
• 🔋 Battery savings – turning off the screen light during a conversation reduces power consumption, which is especially important for low-end models like the Redmi. 9T 6,000mAh battery.
• 👁️ Protection from uncomfortable gestures - in modern firmware MIUI have control gestures (such as swiping down to complete a call) that are easy to activate accidentally.

However, there are obvious downsides to the feature, such as if you use loudspeakers or headphones a lot, automatically locking it becomes useless and turning it off is a necessity, and on the Redmi 9T, the proximity sensor sometimes goes off with a delay, which causes the screen to remain active for the first seconds of a conversation, leading to accidental taps.

Method 1: Disable the lock via standard MIUI settings

The easiest and safest method is to use the firmware settings built in. On Xiaomi Redmi 9T, the path to the desired option may vary depending on the version of MIUI, but the overall scheme remains the same.

1. Open the Settings app (the gear icon on the home screen).
2. Go to the System and Device section → Additional settings.
3. Select Special Features (in some versions of MIUI it may be called Convenience).
4. Scroll down and find the option Autolock screen when talking or Approach Sensor.
5. Turn off the slider next to this option.

If your MIUI version doesn’t have a direct option to turn off, try an alternative path:

Settings → Applications → Application Management → Phone → Permissions → Sensors → Disable “Distribution Sensor”

Open the phone app.

Call another number (such as voicemail)

Put your phone to your ear – the screen should not go out.

Try to turn on speakerphone without unlocking-->

Important! Once the proximity sensor is turned off, the screen will remain active throughout the conversation, which means that random taps are now possible, so it is recommended to use the phone in hands-free mode or with headphones.

⚠️ Note: On some versions MIUI (for example, MIUI 12.5 and later) the option to disable the proximity sensor may be hidden, in which case try updating the firmware or using alternative methods described below.

Method 2: Configure the screen lock delay

If you don't want to shut it down completely, but the standard behavior is annoying, you can set the autolock delay, so that the screen doesn't go out right away, but only seconds after you start talking.

1. Go to Settings → Screen → Sleep mode.
2. Select Delayed Screen Lock (or Screen Timeout).
3. Set the value of 30 seconds or 1 minute.
4. Return to the Special Features section and enable the option to Keep the screen on while calling (if available).

This approach offers a trade-off: the screen doesn't go out instantly, but it doesn't stay on throughout the conversation, which is especially useful if you switch between the speaker and the headphones frequently.

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If your version of MIUI doesn’t have a lock delay option, try installing a third-party app like Google Play’s Proximity Sensor Fix, which allows you to flexibly adjust the behavior of the proximity sensor.

Method 3: Use of an engineering menu (for power users)

If standard settings don't work, you can go to the Engineering Mode, which offers advanced sensor settings. Careful: Incorrect changes can disrupt your phone!

Instructions for setting:

1. Open the Phone app and enter the combination: ##36446337###
2. You will be taken to the engineering menu. Go to the Hardware Testing → Sensor section.
3. Find the Proximity Sensor (approximation sensor).
4. In the Proximity Sensor Calibration field, try changing the trigger threshold (e.g., set 5 instead of the standard 1).
5. Save the changes and restart the phone.

Critical: once the sensor changes, be sure to test it! Call another number and check if the locking of the screen works when the phone approaches the ear. If the sensor stops working at all, return the standard settings.

⚠️ Note: In the engineering menu of Redmi 9T There is a risk of accidentally changing settings that affect the communication or camera. Do not edit partitions that you do not know the purpose of. If after the changes the phone becomes unstable, reset settings through Settings. → System system → Resetting settings.

Method 4: Third-party applications for controlling the proximity sensor

If the built-in settings are not suitable, you can use specialized utilities from Google Play, which allow you to flexibly adjust the behavior of the proximity sensor, including:

• 🔄 Disable the sensor selectively (for example, only for certain contacts).
• ⏱️ Set custom lock delay (from 1 to 60 seconds).
• 📱 Create exceptions for apps (for example, not locking the screen in WhatsApp calls).
• 🔕 Deactivate the sensor completely without interfering with system files.

Top.-3 supplant 9T:

1. Proximity Sensor Fix is a simple solution to disable the sensor with the ability to manually calibrate.
2. Sensor Disabler – allows you to temporarily deactivate the proximity sensor on schedule.
3. Tasker is an advanced automation tool (you can create a rule: "If a call comes in" → turn off the proximity sensor").

Before installing, check user reviews — some applications may conflict with MIUI or require root rights. Also note permissions: if the utility requests access to SMS or contacts without an obvious reason, it is better to refuse to use it.

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Third-party apps are a good alternative if standard MIUI settings don’t work, but they can increase battery consumption and require regular updates to be compatible with newer firmware versions.

Frequent problems and their solutions

Even after setting up the lock screen, Redmi 9T users face typical problems, and consider the most common and ways to fix them:

If none of these methods worked, the reason could be a hardware malfunction of the proximity sensor, in which case it is recommended to contact the Xiaomi service center, especially if the phone is still under warranty, self-repair of the sensor without experience can damage the plume or motherboard.

FAQ: Answers to popular questions