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Hui Fei Type

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MTCB/MTCC and MTCD/MTCE Android Automotive Head Units

The relationship between Chinese designers, manufacturers, brands, and re-sellers is not always clear. Based on wide similarities, but some obvious differences between units, it appears there are multiple manufacturers working from a common reference design.

These units are referred to as "MTCB" or "MTCC" head units, named after the developers - MTC, who also produce the (incompatible but related and very simlar) "MTCD" head units.

They are often sold by sellers such as Eonon, Erisin, Pumpkin, Joying etc. When posting in the forums please DO NOT say things like "I have a Pumpkin XYZ00345" or I have an "Eonon 456GXL" - this will mean nothing to forum members you are requesting help from, please identify your unit by going into settings and pressing "about device", the 2 or 3 letter code before the MCU will tell you who makes your unit (see below). Please quote this at all times in the forums when identifying what unit you have. If this manufacturer code is not prefixed with "MTCB" or "MTCC" then you DO NOT have an MTCB/C head unit, if it is prefixed by "MTCD" then please visit the MTCD head unit page :

One manufacturer - Klyde - substantially revised the MCU firmware and named it "MTCC".These "MTCC" MCUs are fully working on most MTCB units, but not all. The hardware is exactly the same as MTCB units, only the software is different.The latest ROMs from Klyde look for a "C" at the end of the MCU name and if its not there will not work properly. These later KLD 5.1.1 ROM updates ONLY work with MTCC KLD MCUs and the last version of MTCB (MTCB KLD6 v2.85). If an MTCC MCU, an MTCB KLD v2.85 or for MTCB units not made by Klyde, theres a way around it that uses Xposed to change the final MCU letter to "C" allowing later MTCC 5.1.1 + ROMs to work on units with non MTCC KLD MCUs (see here :

The units commonly have a main board mounted in the bottom of the chassis which contains the MCU (microcontroller) which provides non-Android functions such as DVD, video/audio switching, radio tuner and front panel button support. A processor board (SoM - System on Module) containing the Rockchip SoC (System on Chip), RAM, flash memory, and an audio CODEC is commonly mounted behind the front LCD screen. It is this SoM which runs the Android OS.

The firmware is divided into two components, that which runs on the MCU, and the Android OS. These are usually distributed in "mcu.img" and "update.img" files. There are different versions of the MCU (e.g. KLD, KGL, JY, GS). These are associated with a manufacturer's specific implementation, and handle differences in button mapping, radio tuners, bluetooth modules, etc. In general, mcu.img files cannot be interchanged. MCU images are referred to using an abbreviation of the manufacturer's name. Some manufacturers have multiple MCU types (e.g. KLD, KLD2). In some cases, interchanging the firmware for these has appeared to work. Flashing the incorrect mcu.img is not known to cause any permanent damage, but the correct image may need to be flashed to restore proper operation.

The units are generally classified by manufacturer, processor (dual-core RK3066 or quad-core RK3188) and screen size (800x480 or 1024x600). The Android firmware is usually specific to a particular CPU/screen combination, e.g. RK3188/800x640.

A great deal of information regarding these units may be found in this mega-thread, the XDA MTCB/MTCC forums that have been created as a result of its enormous size and in the Hui Fei wiki page.


Known manufacturers (and their MCU identifier) included:


Links to MCU and Android OS firmware

File repositories - FileServer Mega-1 Mega-2

dsa8310 releases lightly modified, pre-rooted MTCB/MTCC firmware which can be found in these threads - 5.1.1. : [1] 4.4.4. : [2] and on the fileserver mentioned above.

Malaysk's firmware, which has features not found in that provided by the manufacturers/resellers. The images are "pre-rooted." RK3066 firmware, RK3188 firmware, MCUs.

booroondook also makes a custom ROM for MTCB, see here [3]

Hal9K latest Android 8.0 Oreo Custom ROM

Coudu's ROMs are no longer being developed

Factory Settings "Passwords"

126 - factory settings menu
3333 - factory settings (only logo change screen)
3368 - factory settings for some Erisin devices (PX5 / es7915v) - MTCE by LEI_MA Lei Electronics Inc
8888 - for factory settings on YT9218c and similar
518 has been reported on some devices - factory settings menu
m123456 - opens Factory Settings in "super" mode -- makes another option visible; Launcher type (a few option tabs not available in standard setup - including changing startup car producer logo, advanced audio settings, tuning the wheel control buttons, etc. Still, it's one of few useful codes)
adbon - seems to enable adb on the usb port. Might enable it for all usb ports (haven't tested it yet)
*#hct#root# - enables persistent root adb on usb port(s) (At least on some units with Android 5.1.1, it doesn't work. It shows 'HCT root' notification, but it doesn't work anyway)
adboff - disables adb on usb port(s)
keject - simulates the eject button for the DVD drive
kpower - simulates the power button
logcan - starts CAN bus logging app
hcttouch - displays information about the touchscreen/calibration?
hctbtup - some sort of bluetooth update mechanism?
hctbtte0-9,0-9,0-9 - some sort of bluetooth testing code -- after the hctbtte there should be 3 digits, ranging from 0-9. Meaning unknown.
sinotech - turn wifi on/off



5.1.1 : Type the code - *#hct#root# into the factory settings password box and press "ok", Install the latest version of King Root from their website [4], open the app and follow the on screen instructions, you need to have an internet connection and maybe some patience as it can take a while, or alternatively install a pre rooted ROM from the link below.
4.4.4 : Type the code - *#hct#root# into the factory settings password box and press "ok", or alternatively install a pre rooted ROM from here : [5]
4.2.2 : Files required:
Root Master 1.3.6 - Mirror1


  1. Download the file above.
  2. Install the APK.
  3. Make sure you are connected to WiFi and you have an internet connection.
  4. Open Root Master
  5. Press the button that says Mulai Root. Chinese characters will flash across the screen for a few seconds
  6. A popup box will appear, press the "Root" button.
  7. More Chinese characters will flash across the screen.
  8. A second popup box will appear, press the purple button.
  9. You are now rooted. Its recommend you uninstall Root Master when finished. Also update SuperUser from the Playstore as this does not install the latest version.

This program connects to servers oversea sending hardware information. The downloads a script that will attempt to root the device. If the first script fails, it downloads additional ones. Future goal is monitor this communication with a data logger and find which script works, so that a unique program can be written to achieve root.

There is also a reported updated to Root Master at: Root Master 2.1.1 but this has not been tested on this device (update, it does work. When you install it, it asks you to update to an even newer version. Do not do it unless you can read chinese. The newest version has different options, all in chinese. Version 2.1.1 just has a button that says "root".) Version 1.3.6 worked on factory rom dated Feb 27, 2014

Bootloader mode

Holding the power button while turning on the unit will get you into bootloader mode. **This is battery power not acc power** The screen will be black but plugging in a usb to the front usb will prompt the PC to install the RockChip bootloader drivers - this might help

System Dumps

The following are two different system dumps. One if splitting of the images from the factory supplied image. These files are untouched from there. The second is a rom dump of a rooted device. Hopefully from these we can find a better way to root, build a recovery made specifically for this radio. And find a way to unlock the bootloader.


  1. Press reset button and power button together
  2. After about 5 secs release reset button, but keep pressing power button
  3. When booting screen appears release power button.
  4. It boots into recovery.
  5. On the KGL-7650G - Power on (battery power) while holding power key without usb connected.

TWRP recovery TWRP recovery working perfect now thanks to Abdul_pt from Freaktab: LINK

You can download from here once you sign in: LINK

To enter stock recovery on Hotaudio units that have no hardware buttons see:

On Xtrons this might work: 1) Hold power button until unit turns off and (on my unit) light flashes. 2) Let go and then press the power button again. This somehow shuts off the unit since it would normally just reboot after releasing the button it seems. 3) Press the power button again to turn it on. It should hopefully go into recovery.

I have no idea if this works on other units, but I have not seen a description of this in any of the posts/videos I have seen.

Latest MCU

Note: Flashing the wrong MCU can lead to incorrect button mapping and/or no radio reception, however flashing the incorrect MTCB/MTCB MCU can usually be reversed by simply flashing a correct one, flashing an incorrect MCU from another unit type such as "MTCD" or a completely unrelated unit can result in a bricked unit. Before updating an MCU, make note of the version which is currently installed, and its Factory Settings. After flashing an MCU, you may need to reset the Factory Settings to their previous values. You should ONLY flash MCUs with the prefix ("MTCB or "MTCC") and manufacturer code (eg KLD, KGL, JY etc) that matches the version already installed, ie KLD MCUs only on KLD versions, KGL MCUs only on KGL versions etc the only exceptions are BN and HA versions which are interchangeable and some KLD MTCB units that can be upgraded to MTCC by flashing an MTCC MCU.

The exception to the above is MTCD/E which are interchangeable/cross-compatible MCUs. Known interchangeable are HA, MLT, JY, KD, KGL and GS. MTCD and MTCE are essentially the same, with MTCE superseding MTCD MCUs. Also note, a tool has been developed for MTCD/E to overcome "Version Unmatch" errors, sometimes experienced when updating MCU between manufacturer types. As of March 2019 the recommended MCU to change to is HA, due to frequency of updates.




Mega - MTCB


Latest Versions


BN-HA: 2.85 | GS: 2.73 | HLA: 2.67 | JY: 2.86 | KD: 2.81 | KGL: 2.83 | KGL1: 2.53 | KGL2: 2.53 | KGL3: 2.84 | KGL4: 2.53 | KGL5: 2.53 | KLD: 2.78 | KLD1: 2.77 | KLD2: 2.78 | KLD2B: 2.81 | KLD5: 2.77 | KLD6: 2.86 | KS: 2.68 | KSP: 2.68 | KSP2: 2.79 | KYD: 2.83 | LZM1: 2.08 | LZM2: 2.08 | LZM3: 2.08 | LZM4: 2.08 | LZM5: 2.08 | MD: 2.67 | MX: 2.82 | RM: 1.85 | RM1: 2.22


KLD5: 2.97 | KLD6: 2.97 | KLD9: 2.98


LM: 1.90 | LM: 1.98


HA: v2.71 | GS: 3.07



MTC Service - petrows

Early start of services/apps, Brightness Control - dsa8310

PCV Startup Builder - devilsoft


Xposed MTC - agentdr8

Malaysk Statusbar Mod - agentdr8

MTC Keys - MVG-V70

Xposed MCU - MVG-V70

MTC Volume - MVG-V70

Xposed Volume bar - 7floor

MTC Sound Control. Hardware guide - 7floor

Modded MTC Apps

Bluetooth Red - Malaysk

Stock apps Red - Malaysk

JY Apps - Malaysk

Various apk mods - hadjistyllis

Red 1024x600 stock mtc modded, More - Marius B

Transparent, More Transparent - Malaysk

JY modded apps - sabruri1

Radio blue - Mat.


Launcher screenshots - Malaysk

Malaysk Rom transparent apps and launcher change video - Malaysk

MTC MCU Tool for decoding/encoding mcu (IDA Pro) - Dark Simpson


Quick list

Wifi: PCB, Case

Mic: Separate internal and bluetooth, MORE

SoM CPU: RK3066 (dual core) can be swapped with an RK3188 (quad core) board

Power button: Add a power button

Powered USB: USB Hub Stepdown buck converter

MTC Sound Processor by 7floor: Android control of audio

Radio low pass filter mod: Pictures and diagram by vaonline

Supported Hardware

Wifi/3G USB dongle:

Front cam: Logitech C930e, Logitech C920

Bluetooth OBDII: ELM 327

Radio signal: Booster Amplifier. Buy antenna booster or power injector. Cylindrical shaped 'boosters' are actually power injectors and will only work if your car has a built in antenna booster, if it does not you will need an actual booster.


3G USB dongle not working: Check APNs. Install Mobile Network Settings

SD Card not working: Make sure formatted to FAT32. SmartDisk FAT32 Format Utility

Factory Settings Password (MCU Settings): 126

Root Access Password (4.4.4 Units, On Factory Settings prompt): *#hct#root#

TomTom not working: Steps (requires change to script)

Sygic not working: HERE, HERE

Schematic diagram for MTCD/E: HERE

MCU Codes

Factory Settings


Bluetooth problem

The internal mic can be bad quality on some units. To correct this install a good external mic and do the hardware mod. Mod instructions are here or here
There are plenty of threads detailing how to make a hardware mod that makes the sound tolerable.

Losing radio station presets

Every time a change is made in factory settings after the reboot, the presets will revert to the original default settings. ExposedMTC has a learn setting that for the most part will prevent this.

Flashing MCU

Flashing the wrong MCU is known to cause the radio to stop working and the buttons to be mapped incorrectly. To prevent this, use the "Export" function in factory settings prior to updating the MCU, this will add an "MCU config" (mcu.cfg) file to your sd card card and the MCU settings will be flashed along with the new MCU.

Delay shutdown not working

If the MCU is older than v2.5 the feature is not available. Otherwise check that the HU has constant power. There are reports that some ISO adapters are wired incorrectly.
Some cars cut or drop voltage to the IGN (usually red) cable during cranking ('powering off' message then apps reset after engine starts) and engine shutdown (prevents the MCU from managing shutdown delay). Sometimes is fixed by adding a diode+capacitor solution

Deafening Beeps upon start up

In factory setting under audio. Its the system sound setting. Turn it down.

No element menu

Factory setting - Other - RGB LED make sure set to RGB (will ONLY work if your unit actually has RGB LEDs)

Install apps from unknown sources grayed out

Factory Settings - Other - unchecked Disable App Install

Insufficient memory to download an app even though there is plenty of free memory

This issue appears to be a cache problem. There is only 1GB of space allocated for programs.
First option is to uninstall several programs until you are allowed to install a program. Then install a cache clearing app.
Second is to install a custom ROM such as a mildy modifed, pre-rooted ROM from @dsa8310, or a full custom ROM like @Malaysk's or @booroondook's, these all have at least a 2Gb app partitions.
Third Option. Reallocate the partition size. here
Malaysk's Roms can be found here

Using the OBD II


The OS is looking for a device named OBD if your reader has another name it will not connect.
XposedMTC has a fix for this. Install Xposed Framework, then ExposedMTC


Upgrade MCU and Android to the latest available version or 3rd party Android such as Halk9K.
Once updated, change Android BT pin to 1234, remove any existing pairings and then try pairing your Bluetooth OBD unit.

Volume knob not working

Factory setting -other - disable Wheel3

Shows wrong door open

Factory setting - other - disable rudder
Rudder is so you can tell the unit if your car is right-hand drive or left-hand drive

"SD Card is missing..." error

Due to the internal_sd not mounting. In Settings->Storage, if you find the internal_sd sd card and clicking on Mount doesn't do anything, erase it, and it should init to 11GB+ (depending on rom).