How to Connect/Flash BLHeli_32 ESC via FC Passthrough

I received my first BLHeli_32 ESC’s, and I’d like to share how to connect them using “FC passthrough” to the BLHeliSuite32 configurator app, and how to flash the latest firmware on these ESC’s.

“FC pass-through” is the easiest way to connect to your ESC, which works similarly to the previous BLHeli_S. Basically it uses the flight controller as a programming tool for the computer to talk to the ESC’s directly. Therefore you can change settings or flash new firmware to the ESC’s using the FC’s USB connector, without taking the ESC’s out of the quad.

Software Requirement

  • Betaflight V3.2 or newer firmware on your flight controller
  • Download latest BLHeliSuite for BLHeli_32 from (link in the section at the very bottom – read me)

Hardware Requirement

Make sure that your ESC’s are indeed BLHeli_32 compatible. Mistakenly flashing BLHeli_S ESC’s with 32-bit firmware can “brick” your ESC’s and it’s irreversible.

REMOVE YOUR PROPS before continuing…

With your BLHeli_32 ESC connected to the FC, and powered by LiPo battery.

When flashing firmware, make sure your computer is connected to the internet! BLHeli32 checks online whether your ESC is legit or not. But changing settings is totally fine without internet, so you can configure that in the field :)

Now you are ready!

Connecting to BLHeliSuite32

  • In the BLHeliSuite32 configurator, click “Select BLHeli32 interface” in the menu bar, and choose “BLHeli Bootloader (Cleanflight)”
  • At the bottom of the program, choose the COM port of your flight controller in “Port”, and click “Connect”
  • Once it’s connected, click “Read Setup” and the settings of your ESC will appear

Flashing BLHeli_32 Firmware

The only time you need to flash BLHeli_32 firmware is to update them to the latest version. If you can connect to the ESC without problems, flashing should also work.

Make sure your computer is connected to the internet for flashing ESC’s, otherwise you will get an error “Unable to establish server connection”. BLHeliSuite_32 checks whether your ESC’s are genuine upon connection.

REMOVE YOUR PROPS before continuing…

Launch BLHeliSuite32 program, connect your FC to computer via USB and plug in your battery to power up the ESC’s. On the bottom of the program select the COM port of your FC and click “Connect“.

After it’s connected, click the “Check” button.

Back up your settings! Take some screenshots of your settings for each ESC just in case something goes wrong and you can still go back.

In BLHeliSuite, click “Flash BLHeli“, and click the button “OK”.

You will be prompted if you want to flash this firmware, click “Yes” and the flashing will begin.

When the firmware flashing is done, the program will ask if you want to write current settings to your ESC’s, click Yes if you want to retain your previous ESC configuration.

When this is done, it will move on to your second ESC. Repeat the same steps you just did until all 4 ESC’s are updated.

When it’s done, click “Disconnect” in BLHeliSuite, unplug your battery and plug it back in to restart your ESC’s. Check your ESC settings and make sure they are correct, such as direction and other parameters.


I can’t connect to my BLHeli_32 ESC with pass-through even with the latest BLHeliSuite32 app. My FC is loaded with the latest firmware. However I can connect to other ESC (not 32bit) without problem with the old BLHeliSuitE.

Your FC is probably not V3.2. You are using the latest stable release which is V3.1.X. V3.2 is not released yet and you need to download it from the link above and load it locally.

I am getting an error when trying to flash new firmware: “Unable to establish server connection!”.

This error occurs when you have no working internet connection on your computer. BLHeliSuite32 checks if your BLHeli32 ESC’s are genuine before flashing new firmware to them. No internet, no check and thus it fails.

I am getting error “Initialization of serial 1wire passthrough or 4way interface failed! Please check Betaflight revision for support of serial 1wire passthrough or 4way interface!”

I was also getting this error when using my Naze32 (F1) flight controller, even with Betaflight V3.2 already installed. I had no way around this error, and I had to use a F3 FC in the end. Maybe BLHeli32 passthrough is not supported in F1 FC’s.

Edit History

  • Jun 2017 – article created
  • Nov 2018 – Both Betaflight/BLHeli_32 are out of beta. Added steps how to flash ESC

34 thoughts on “How to Connect/Flash BLHeli_32 ESC via FC Passthrough

  1. K Raghavendran

    Dear Oscar,

    This is my first Dshot based ZMR250 Build.

    ESC : Blheli 32 Dshot 50A Escs
    FC : Dalrc f405 AIO

    RX and Tx : Trananis X8R and Taranis Q X7

    Problem that I am facing:

    1.ESC emit only 3 Beeps instead of 5 Beeps when I connect my battery.
    2.Motors do not Spin
    3.I cannot connect ESCs to BlHeli Suite.

    Serial Interface ”m4wFClntf” connected successfully
    Connection to ESC#1 failed!
    Please check data- und power-connections to the ESC!

    Where i might have messed up:

    1.Didnt know that Dshot doesnt need esc calibration.
    2.I raised the Throttle Stick high on the TX and connected the battery to the FC like PWM, PPM etc.
    3.After this point, ESC Beeps only 3 Times.


  2. ArcherFPV

    I just finshed a build today and updated to newest betaflight 3.5.3 but when I go to motors tab to test motors, motor 1 isn’t spinning. I go to blheli 32 and it says esc 1 not found. Im running the Dalrc F405 and Engine 40a 4n1 esc. im able to connect to blheli 32 and was able to flash the other 3 escs to the latest fw but of course cant flash esc 1 :-( any insight on what could be going on?

    1. Oscar Post author

      double check ESC connector, make sure the ESC signals are connected to the FC. Otherwise it sounds like a faulty ESC, contact your reseller see if you can get a replacement.

      1. ArcherFPV

        Thanks for the info. It’s taken me 2 months but I finally got the vendor to send me a new one this week. Seems that dalrc didn’t verify that all the esc’s on the board were flashed before they shipped it out. Apparently there were quite a few people with the same issue on the same esc 1. Others it was 2 and 4. Hopefully it doesn’t take a month to get here. I really want to fly that rig.

  3. Wey Fun


    I am using a AirBot’s Omninxt F7 controller with a Racharlance Fort32 40A 4-in-1 ESC. When I connect the controller via USB and power up the ESC with 6S Lipo, the BLHeli32Suite says “Found 2 ESC with similar unique ID numbers!” . The controller comes with Betaflight 3.4.0 so should not be problem.

  4. Benjamin

    I have a kakute f4 Flight Controller (v1 not v2) running/flashed on Betaflight 3.2.0 And im using BLheli 32bit 30 amp ESC’s Running Dshot 600 and when I try/want to connect BL Heli Suite 32 I keep getting the same error which I cannot find a fix using google/forums searches…Help would be greatly appreciated.

    MY error is :
    Connection to 4-way interface “m4wFCIntf” succeeded.
    Found outdated Protocol revision 106!
    Please update the Interface to a supported revision!
    (protocol 107 or higher)
    Now like I mentioned I cannot find a solution to this problem using google searches and multiple forum searches.

    Any insight?

  5. Andrew Brahim

    Oscar, I found your article helpful, but I’ve ran into an issue with the speed controllers not being found in blheli suite. I first thought it was my servo pins on my Sp racing f4…but it looks correct. Also the escs only light up momentarily when I connect the battery but then turn off. I’m running lumenier 51 A x4 and a 6S battery. I’m trying this with no motors connected…could that be the cause of my error?

  6. confidentcar .

    I was setting up a lumenier 4 in 1 esc 35 amp but by mistake i opened it with blheli s instead of blheli 32 and i flashed the latest blheli s version therefore i briked the esc. Now when i connect blheli 32 it recognize that it has a corrupted file and it tries to erase it but is unable to complete the process, i can not find the proper .hex file to download and manually. Do you have any suggestions?

  7. Rob

    I am constantly getting an error message whenever I try to Read Setup.
    It states
    Serial Interface “m4wFCIntf” connected successfully.

    Connection to ESC#1 failed!
    Please check data- and power-connections to ESC!

  8. nick murphy

    i just wired my “makerfire blheli_32” esc’s to a bff4 board and in blheli 32 suite its saying connection to flight controller failed check usb serial port and power connections. my wiring is good and i have bf 3.2 flashed already. the motors spin from the motor tabs so i know theyre connected. what do i do?

    1. Oscar Post author

      Are you powering up the ESC’s with battery before connecting?
      Also check with Makerfire if they are actually open for connecting to the configurator.
      I had some ESC’s from DYS and that batch was actually locked and i was unable to connect to BLHeliSuite with them.

  9. -G FPV

    Oscar, I’ve been working on new build using the Betaflight F4 along with the Betaflight 32bit 35a ESCs. While in the Betaflight program all four motors spin up correctly and everything seems fine. Turtle mode will activate however the motors do not spin backwards like they should. I’ve downloaded BLheli_32 to try to reflash the ESCs but ESC number four is intermittent and ultimately not found in BLHeli_32 when singled out. I’ve reflashed my FC with the lastest stable version of Betaflight 3.2 and still running into the same problem. Am I over looking something?

  10. phillip pedigo

    Naze32 Rev 5 – BetaFlight 3.2.1 – I am getting an error when i Read Setup on BLheli Suite. Plug in USB to FC then “Connect” in BL heli suite, then plug in batter, then hit “Read Setup”. No worky. “Found Multiple ESC Configuration in SiLabs mode: ESC# 1: –“. I have tried flashing the FC with Betaflight 2.7 (read this in a post and it seemed to work for the guy) still didnt work. Using BLHeli suite 16 and 32 both come with error. Please help!

  11. Jon

    Thank you for the education and walkthrough Oscar. I put it to use tonight and managed to configure everything successfully on my first set of 32b ESC’s :)

  12. ChuckH

    Hello Oscar,

    So I am trying to setup my flight controller and esc’s and am having a hard time getting everything set up. I am new to all this quad stuff so bear with me. I have flashed my FC Naze32 with cleanflight 2.1 and I have been tryiing to setup my esc’s with BLheli suite. If I am not using Betaflight 3.2 should I be using the BLheli suite16 instead? When I attempt to connect to my esc’s with the BlHeli configurator they do not connect at all. When I use Suite32 it kind of connects meaning Suite 32 will read the esc’s and it knows that there are four, but it will not spin them up or allow me to make individual adjustments and such.

    I am sure i need to back up a step to get everything working, what suggestions can you give me?

    1. Oscar Post author

      No, “BLHeliSuite_32” is for 32-bit ESC’s, and you must have the latest Betaflight 3.2 installed on your FC.
      If you are not using 32-bit ESC then just use “BLHeliSuite”, and it should work on Cleanflight and older BF firmware.

  13. Danny

    i have the Matek F405 FC and cant connect to BlHeli32 suite im getting the :

    “Initialization of serial 1wire passthrough or 4way interface failed! Please check Betaflight revision for support of serial 1wire passthrough or 4way interface!”

    ive tried everything and i have same setup on another quad and no problems at all
    motors spin fine but the escs will not connect to Blheli32 suite

    any help?


  14. Bryan D Wolfe

    My ESCs program in BLHELI_32 fine, but when I use the motor tab in BetaFlight Motors 1-3 spin fine but NOT motor 4. The ESC LEDs are on, it reads and programs fine, swapped motors to a knowing working motor, swapped ESC from its original position of 1 to now 4 and same issue. Any idea what is going on?

    1. Oscar Post author

      The LED only indicates the ESC is getting power. My guess is that your motor output on the FC is bad..
      if you have a spare motor pin, use it.

    2. Dirk

      Similar issue here. With using dshot150 only motor 1-3 are spinning.
      BUT if I disconnect the receiver (MPX) everything works fine!
      So the XBUS_MODE_B seems to disturb the communication with the ESC. Also the motor setup with the suite does only work properly without receiver connected.
      Multishot is working also with receiver on…

  15. Oyvind

    Trying to connect to my Littlebee Summer 2-6s BLHeli_32 30A esc’s from the latest BLhelisuite. I am not able to load BLheli32 interface profile, Cannot read settings, or flash firmware. All motors spin in the motor test just fine. Also in Betaflight.. I have flashed my FC to Betaflight 3.2 RC4, so it should be fine. FC is Matek F405-AIO. Any ideas?

  16. Daniel

    My first comment here and would like to thank all the people that invest their time to make this site happen. I’m new to the hobby and many times this site guided me along through the steep learning curve for a beginner like me. Great job!

    I’m trying to test my motors using BF or BLHeliSuite32 but I cannot make them spin. Previously, on BF v3.1.7 I was able to go in motors tab and spin just 1 motor ( from 4 ). Later I discovered that ESCs where taking a lot of time to get “read” by BF as eventually I could spin 3 motors. I kind of gave up on the last as it was taking too much time.

    After the BF update and even on BLHeliSuite32, there is no way I find out how to make motors spin from the “motors” tab. On BF sliders are disabled and it won’t work on BLHeliSuite32, although it says that it can read setup for all motors. Is this bad and if so, is there any reason why this might be happening? I’m afraid something is wrong with my ESCs or my setup.

  17. casey hanke

    Anyway to do this with raceflight? I have the new skitzo board and im trying to get raceflight to see them

    1. Pyrolassist

      Am I also building a new quad with Skitzo (Raceflight) and was wondering the same? Has anyone successfully used BlHeli_32 and raceflight together?


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