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: http://192.168.8.1/html/switchProjectMode.html. 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.

Preconditions

• I’m on Windows 10.
• The product’s full device name is E5330Bs-2.
• Hardware version is CH1E5330SM.
• Firmware version is 21.210.09.00.1080.

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 asiantuntijakaveri.fi[2]. It’s a large collection of tools to flash the firmware of Huawei Modems.
  • Alternatively, download only the command line script from [7]
• Extract and unzip the folder “[3] Switchmode E3372h”
• Verify that your MiFi router is reachable under http://192.168.8.1/ 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
  • AT^VERSION?
• 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.

Links

• • [1] Collection of tools to flash a new firmware to your Huawei – includes the switch mode command line tool
  • [2] Convert Huawei E3372h-153 from HiLink/router-mode to Stick/modem-mode – The first steps include the activation of the COM port mode
  • [3] Huawei-Debug-and-Project-mode-drivers-FcSerial – Drivers for the serial COM ports of the Huawei E5330
  • [4] Putty homepage – Terminal emulator
  • [5] Description of AT^SYSINFO – Reference book for AT commands
  • [6] Huawei E5830 / E5832S / E585 / E586 und MultiSim + Update für neue Huawei Geräte – German tutorial to disable CS mode, relies on switchProjectMode.html
  • [7] Command line tool to switch project mode – a .zip file download. This is an alternative to [1].
• Huawei Set Modem Mode 3G/GPRS – More details about the available options in the mentioned SYSCONFIG command