Connecting external audio devices via AUX input on a radio with Android Auto or clean Android often raises questions among owners. Despite its prevalence, the analog connector remains in demand due to the stability of the connection and the absence of audio delays. However, many users are faced with the fact that the input is either not activated automatically or is not available at all in the settings menu. Bluetooth And USB, analog connector 3.5 mm remains in demand due to the stability of the connection and the absence of audio delays. However, many users are faced with the fact that the input is either not activated automatically or is completely absent from the settings menu.

The problem is complicated by the variety of firmware: on some radios (for example, Pioneer AVH-X or Joying JY-UQ128) AUX is enabled through the engineering menu, on others it requires a software update. In this article, we will look at all activation methods, from standard to hidden, and also consider typical errors due to which sound may not be transmitted.

If your radio does not recognize the connected device, this does not always mean a malfunction. More often the culprit is the settings audio routing —the system that determines where to play the sound from: from Bluetooth, USB, FM or AUX. On some models (for example, Xtrons PB7868B), priority is given to wireless connections, and the analog input is blocked by software.

Before proceeding with the settings, make sure that:

  • 🔌 Cable 3.5 mm is working (check on another device).
  • 🔊 The volume level on the connected device (smartphone, player) is set to maximum.
  • 🔄 The radio is not in mode Mute or Phone (on some firmware AUX is disabled when there is an active call).
📊 What radio are you using?
Pioneer
Joying
Xtrons
Atoto
Other
I don’t know

1. The standard way to enable AUX: search in the settings menu

On most radios with Android 8.0–12 input AUX is activated through the basic sound settings. Algorithm of actions:

  1. Start the radio and go to the main menu (usually a button Menu or a gear icon).
  2. Select a section Settings → Sound (or Audio Settings).
  3. Find the item AUX Input, Line-In or External input. On some firmware it is hidden in the submenu Sound source (Sound Source).
  4. Activate the switch (if there is one) or simply select AUX as the current source.

If the item AUX is not in the list, this may mean:

  • 🔧 The input is disabled in the engineering menu (see section 3).
  • 🔄 Firmware update required (relevant for Atoto A6 and Dasaita until 2022).
  • 🚫 The connector is not physically connected to the board (check the documentation for the model).

Important! On some radios (for example Eonon GA2166) AUX is activated only when the cable is connected. Try inserting the plug 3.5 mm into the connector and open the settings again.

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If there is sound after activating AUX distorted or quiet, check the equalizer settings. On some firmware, a separate profile is used for the analog input Line-In EQ, which can be reset in the menu Sound → Equalizer.

2. Activation through the engineering menu (for hidden settings)

If AUX is not is displayed in the standard settings, it can be enabled via engineering menu (Engineer Mode). This method works on most radios with processors Rockchip (for example, Joying, Xtrons) and MTK (Atoto, Dasaita).

Instructions for Rockchip: 

1. Go to Settings → About phone (or About Device).

2. Find the item Build number (Build Number) and tap on it 7 times until a notification appears You have become a developer.


3. Return to the main settings menu - a new section will appear For developers (Developer Options).


4. Turn on USB debugging and connect the radio. to the PC.


5. Enter the command in the terminal:

   adb shell am start -n com.android.settings/.EngineerMode

6. In the engineering menu, find the tab Audio and activate Line-In Enable.

For radios on MTK (for example, Atoto S8):

  • 📱 Enter the code ##36446337## in the application Phone (if it exists).
  • 🔊 Go to section Hardware Testing → Audio → Line-In Test.
  • 🔧 Turn on Enable AUX and save the settings.
What to do if the engineering menu does not open?

On some firmware, access to Engineer Mode is blocked. In this case, firmware via SP Flash Tool (for MTK) will help. or Rockchip Batch Tool with a pre-modified file settings.dbwhere the parameter is specified persist.audio.aux.enable=1. The operation requires experience and may lead to loss of warranty!

On radios with a processor Qualcomm (for example, Pioneer DMH-WT7600NEX) the engineering menu may be missing. In this case, AUX is enabled only through the official software Pioneer ARC or WebLink.

3. Checking the physical connection of AUX

If the software methods do not work, the problem may be in hardware. (for example, Klyde SK02 or Hizpo) are sold with an unconnected connector 3.5 mm —it needs to be soldered yourself or at a service center.

How to check:

  1. Remove the front panel of the radio (usually secured with latches or screws under rubber plugs).
  2. Find the connector on the board AUX_IN (marked as LINE-IN or AUDIO-IN).
  3. Make sure that the cable is connected to it from the socket 3.5 mm on the front panel.

Typical connection patterns:

Color wires Purpose Where to connect
Red Right channel (R+) To contact R_IN on board
White Left channel (L+) To contact L_IN
Black/metal General (GND) To any contact GND on the board

⚠️ Attention: If you are not confident in your soldering skills, do not take risks - an incorrect connection can damage the audio amplifier of the radio. Contact the service center indicating the device model.

4. Firmware update to activate AUX

On radios with outdated firmware (especially on Android 6.0–7.1), the input AUX can be disabled at the kernel level. The solution is to update the software to the latest version.

Step by step instructions:

  1. Download the firmware for your model from the manufacturer's official website or forum 4PDA (for example, for Joying — joyingauto.com).
  2. Unpack the archive and copy the files to MicroSD (format FAT32).
  3. Insert the card into the radio and go to Settings → System update.
  4. Select the firmware file (usually update.img or firmware.zip) and confirm the installation.

After the update:

  • 🔄 Reset the settings to factory settings (Settings → Recovery and reset).
  • 🔊 Check the appearance of the item AUX in the sound source menu.

⚠️ Attention: Firmware from unofficial sources may contain viruses or unstable drivers. Always check the file hash listed on the manufacturer's website. MD5-file hash specified on the manufacturer’s website.

☑️ Preparation for firmware

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5. Alternative ways to connect external audio

If you cannot turn on AUX, consider alternative options:

  • 📱 Bluetooth adapter with 3.5 mm: Connect to the radio Bluetooth transmitter (for example, Tronsmart Apollo Bold) and connect it to an external device via wire. Minus - sound delays are possible.
  • 💽 USB audio card: Some radios (for example, Atoto S8 Ultra) support external USB audio cards. Connect the adapter USB → 3.5 mm and select the source USB Audio.
  • 📻 FM transmitter: Use a device like Nulaxy KM18that transmits sound via FM frequency. The quality will be worse, but the method is universal.

For radios with Android Auto (for example, Pioneer AVH-Z5200BT) you can use the application SoundAbout iz Google Play:

  1. Install SoundAbout and provide rights ADB (if required).
  2. In the application settings, select Media Audio → Wired Headset.
  3. Connect the device via 3.5 mm - the sound will be redirected to AUX.

6. Troubleshooting: why AUX does not work

If the input is activated, but there is no sound, check the following points:

Problem Possible cause Solution
The sound is distorted (wheezing, noise) Bad contact in the connector or faulty cable Clean the socket 3.5 mm alcohol, try another cable
There is sound, but very quiet Incorrect gain settings in the engineering menu In Engineer Mode → Audio increase Line-In Gain to 100%
AUX turns on, but immediately turns off Conflict with other sources (Bluetooth, USB) Disconnect all other devices and reset sound priorities

On radios with Android 10+ protection against “unauthorized sound input” may be triggered. To disable it: 

1. Activate developer mode (see section 2).

2. In Settings → For developers find Disable audio effects and enable it.


3. Restart the radio.

⚠️ Attention: On some Chinese radios (for example, Hizpo T9) AUX only works when Android Autois disabled. Try exiting the application or disabling it in the settings.
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If after all the manipulations the AUX does not work, check the radio on another machine or with a different sound source. This will help determine whether the problem is in the device or in the car electrics (for example, a bad ground).

Frequently asked questions

Is it possible to enable AUX on the radio without a physical connector 3.5 mm?

No. AUX is an analog input, and without the corresponding socket on the radio board it will not work. An alternative is to use an Bluetoothadapter or USB audio cardif they are supported by your model.

After the firmware update, the AUX item in the menu disappeared. What should I do?

Reset the settings to factory settings (Settings → Recovery and reset). If it doesn’t help, flash the radio to the previous version of the software or contact the manufacturer for a patch.

On my radio Pioneer There is AUX, but the sound goes only to the two front speakers. How to fix it?

This is a firmware limitation. In the engineering menu (Pioneer ARC) find the section Audio Output and enable the option Full Range AUX or 4CH Line-In.

Is it possible to connect a microphone to the AUX for karaoke?

Technically yes, but most radios do not support recording sound from 3.5 mm. For karaoke, it is better to use specialized devices with an input Mic-In or Bluetooth microphone.

How to check if AUX works on the radio before purchasing?

Connect to connector 3.5 mm smartphone or player and start the music. If there is no item in the settings AUX, but there is sound, the input is activated by default. If there is no sound, ask the seller to show the engineering menu.