how to unlock modem

Since I’m working on remote automation system development, I’ve been playing a lot with this Wavecom GSM Modem on my development since I use it for GPRS connection. The issue is, when I use a new SIM card, sometimes that SIM card have pin number which make the modem locked and cannot dial or connect to the internet via GPRS until I unlock the GSM Modem by issuing the pin number. That was annoying when you have put the pin number every time it is booting while you suppose to just leave this device to work and connect automatically.

Actually, in order to fix this issue, I can just disable the SIM card pin. So, I would like to share my routine with new SIM card with pin number, assuming you knew some AT+Command basic and how to use it. Here’s how to disable your SIM card pin via Wavecom Meastro, Fastrack or any compatible GSM modems:

    1. Connect your modem to your computer.


    1. Open up serial terminal. I’m using minicom coz I’m on Linux box. On Windows, you can use HyperTerminal.


    1. Turn on your GSM Modem


    1. Issue an AT command to test it. You may want to change to the right baudrate in order to get the reply:
      the expected reply is:


  1. Check if the Modem is locked by the SIM pin by issuing:

    the expected reply for unlocked modem should be:

    or else, you have to unlock it by issuing: (example: my default SIM card pin is 1234)

    and it will reply OK

  2. Now, we can disable the pin by issuing:

    where 1234 is your current SIM pin.

That’s all. You can now restart the modem and use it with your automated GPRS dialer. I don’t know if this GSM AT Command will also works on siemens gsm modem or other GSM modems. You can try it and feel free to leave your comments. Have fun


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