Fix “busy line bug” of Huawei E5330 without switchProjectMode.html

The Huawei E5330 is a MiFi router that has the bad habit to block the SIM for incoming calls, causing the phone line to appear busy. You find a lot of guidance online, including a step to call a hidden website: However, that webpage “switchProjectMode.html” does not exist on Huawei E5330. This blog post describes an alternative, end-to-end solution.

 What’s the problem?

  • The Huawei E5330 operates in Circuit Switching (CS) mode, so it can also receive SMS text messages. For no good reason, it also responds to incoming phone calls by sending a “busy signal” to the caller.
  • This is highly problematic if you have multiple SIM cards linked to one phone number. There doesn’t seem to be an agreed industry term for this, but German providers call this MultiSIM, UltraCard or Multicard. One SIM is in your phone for calls and mobile data, the other might be in your MiFi router for data only. Now when your Huawei device blocks phone calls, you can no longer be reached on your phone!
  • One workaround is to set the MiFi router to Packet Switching (PS) mode. That way it has no longer access to the phone line.
  • Tutorials and forum posts online recommend to do the following:
    • Connect the device via USB to your PC
    • Switch to “COM port mode” using switchProjectMode.html
    • Send the AT modem command “AT^SYSCFG=2,2,3FFFFFFF,1,1” to the device’s COM port to switch to PS mode
  • While a few people claim to have succeeded with these steps, my Huawei device doesn’t seem to serve this hidden website. I’m always being redirected to the device’s homepage.

The following chapters describe step-by-step how to do the same without switchProjectMode.html.


  • I’m on Windows 10.
  • The product’s full device name is E5330Bs-2.
  • Hardware version is CH1E5330SM.
  • Firmware version is

Switch Huawei E3550 to serial mode

  • Before turning it on, connect the router to your PC via USB and wait for it to boot.
  • When the battery icon turns on permanently, hold the “Power on” button, until the device starts the actual router mode.
  • Open the “Device Manager” in Windows’ Control Panel. In section “Network adapters” search for “Remote NDIS based Internet Sharing Device”. If you don’t find it, the device is likely to be still in “CD/DVD drive mode”, so repeat the steps from before.

    MiFi router appears as NDIS device in Device Manager
  • Download the .zip file[1] from[2]
  • Extract and unzip the folder “[3] Switchmode E3372h”
  • Verify that your MiFi router is reachable under and log in. Default credentials are “admin”/”admin”.
  • Run the “sw_project_mode.cmd” script
  • Back in the Device Manager you should find “Unknown devices”. Those are the router’s COM ports.
  • Install the FcSerial drivers[3]
  • If not instantly, at latest after a reconnect you should find the COM ports in the Device Manager’s section “Ports (COM & LPT)”
  • Remember the “PC UI” port’s name. COM5 in my case.

    Correctly installed COM ports of the Huawei E5330 router

Connecting to the COM port and enabling PS mode

  • I recommend Putty[4] as a terminal emulator to connect to the serial console. It allows you to paste commands, which will be very useful and safe as well. There is also a portable version on other websites.
  • In Putty, connect to the COM port.
    Necessary and optional settings in Putty

    If the connection can’t be established, have a look in the “Serial” options in the left menu. You can try the same settings as you find them in the “Properties” dialog of the COM port in the Device Manager.

  • You should disable the mobile data connection of your router by now. Otherwise the terminal will be spammed with output.
  • Once you are connected, make yourself comfortable with the shell by sending these harmless commands followed by Enter:
    • ATE1 – activate this command to see your typed keys in the console!
    • ATI
    • AT^FHVER
  • Check your current system’s state with “AT^SYSINFO”. The values are explained here: [5].
  • Now, most important, change your config with
    • AT^SYSCFG=2,2,3FFFFFFF,1,1
    • wait a few seconds for the command to be processed
    • Source: [6]
  • Close the terminal.
  • Restart the device.

You’re done!
Let me know in a comment, if this worked for you or not. 🙂
If the download links are broken also let me know, so I can provide a mirror.



19 thoughts on “Fix “busy line bug” of Huawei E5330 without switchProjectMode.html”

  1. Thank you very much! This article is so helpful for me. It all works perfect. I have the same hardware and software version but Windows 7 and a trial version of “Hyper Terminal Private Edition”.

    Liked by 1 person

      1. Yes it does allow copy&paste and it also shows all the commands you are typing in. The only reason I’m using Hyper Terminal was because i have installed it before. 🙂 It was mentioned in another article which didn’t worked for me.


  2. Vielen Dank für die sehr gute Anleitung. Ich habe 8 Huawei E5330 wieder zum Laufen gebracht.
    Du musst nur bei der Putty Konsole erwähnen das der eingegebene Befehl nicht sichtbar ist
    Vielen Dank



    1. Hallo Jürgen,
      gleich 8 Stück? Wow!

      In jeder Konsole ist nur sichtbar, was das Gerät sendet. Damit zu siehst, was du tippst, muss das Gerät in den “echo Modus” gehen. Deswegen hab ich im Artikel auch als ersten Befehl ATE1 empfohlen 😉

      ATE1 – activate this command to see your typed keys in the console!


  3. Hi Peter,

    Thank you for the tutorial. Great stuff! With small modifications I was able to fix the “line busy” bug on a HUAWEI LTE stick E3372. Instead of COM5 my PC UI Interface was found at COM21.

    However, I had to slightly modify the AT^SYSCONFIG command to:

    I found this command line here:

    After using your command “AT^SYSCFG=2,2,3FFFFFFF,1,1” I only had 2G connectivity.

    Not real easy for me to find out which value is which. Maybe you can comment?
    Thanks again,

    Liked by 1 person

    1. Hi Arne,
      great to here that my post was helpful!

      Which COM port has to be used will vary from case to case. I think your operating system will chose a port on demand. That’s why you have to look up the correct COM port number in the device manager.

      I have no more information about the SYSCONFIG commands, that’s why I linked to and others.

      Best regards,


  4. Vielen Dank!
    Klappte für mich (musste nur die Ziel-IP in der .xml-Datei ändern.
    Hardware-Version: CL2E3372HM


    1. Hallo zusammen.
      Unglücklicherweise hat das E8231 keinen Power Button, so dass die Anleitung für dieses Gerät nicht funktioniert. Hat es schon mal jemand mit einem E8231 erfolgreich durchgeführt? Und wenn ja, wie?


  5. Hallo Peter.
    Habe Deine Antwort erst jetzt gesehen. Yep – Er kommt unter Windows 10 als NDIS Gerät an.
    Gruss – Klaus


    1. Ja ok, aber dann ist doch alles cool – selbst wenn du keinen Power Button hast. Wenn dein Gerät bereits von sich aus als NDIS-Gerät angezeigt wird, dann machst du in der Anleitung einfach weiter ab dem Punkt:
      >>> Open the “Device Manager” in Windows’ Control Panel. In section “Network adapters” search for “Remote NDIS based Internet Sharing Device” <<<


      1. Hallo Peter.

        Hat etwas gedauert, aber heute habe ich endlich Zeit gefunden, die Prozedur durchzuführen. Hat schlußendlich alles einwandfrei funktioniert, hatte nur etwas Trouble mit Putty. Der Stick, bzw. Das Modem hat ständig etwas in die Console gepostet, so dass ich nie genug Zeit hatte, das Kommando fertig einzugeben. Abhilfe: Das Kommando in Notepad fertig eingegeben, in die Zwischenablage kopieren und dann im Konsolenfenster rechte Maus (Das fügte bei mir zumindest das gesamte Kommando ein), und dann schnell ENTER drücken.

        Das Originalkommendo von Dir wurde bei meinem E8231 mit Fehler beantwortet. Dann habe ich das Kommando von Arne (für G3) benutzt, und das wurde mit OK quittiert.

        Getestet und alles gut! Perfekt! Nun kann ich über den Stick ins Internet und gleichzeitig auf meiner Multi-Sim angerufen werden und telefonieren.

        Also auch von mir nochmals ein herzliches Dankeschön für die perfekte Vorarbeit.

        Gruss – Charly


  6. Wenn ich bei meinem E5573 den Befehl “AT^SYSCFG=2,2,3FFFFFFF,1,1” eingebe kommt nur Error.
    Hat jemand eine Idee wieso? Habe die Anleitung genau befolgt…


    1. Hi Niklas,
      hast du keine Fehlermeldung dazu bekommen?
      Schau mal in den verlinkten Artikeln, wo ich das Kommando her habe. Dort gibt’s vielleicht auch Kommandos speziell zu deinem Gerät.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s