Calypso firmware update (work in progress), fix for #666 '3G-SIM not recognized'

Dieter Spaar spaar at
Tue Nov 18 10:02:14 CET 2008

Hello Dima,

Dima Kogan wrote:
> I'm still unsure about whether #666 has gone away or not. At first my
> sim seemed to work much better with the new firmware, but now it
> doesn't seem to work at all, with any distro. It's such a consistent
> failure now, that I'm no longer sure I'm seeing #666. Can somebody post
> some AT commands that I can issue to talk to the modem to query its SIM
> and network registration status? Thanks!
Detection of the SIM and Network registration are different things, 
however a
SIM has  to be detected first to register on the network.

Here are some AT commands to check if the SIM is detected. I assume that
the GSM  modem has just been powered on and no AT commands have been
sent yet:

Fist of all, turn extended error messages on:


Now turn GSM on:


If there is a SIM which does not require a PIN, you receive:


If there is no SIM or the SIM is not detected, you receive

+CME ERROR: SIM not inserted

If there is a SIM and it requires a PIN you receive:

+CME ERROR: SIM PIN required

If a PIN is required, send the following where "xxxx" is your PIN:


After the PIN has been sent, you can send again


If you want to do some simple check if the SIM is working, send:


and you should get

+CSIM: 4,6E00  

This is a smart card APDU with a class which is not detected by the card
and so it returns an error (6E00). This command works on all firmware

A working APDU is


which returns

+CSIM: 4,9F16

This selects the MF (master file) of the smart card, this command only
works with "moko10",  older versions return

+CME ERROR: operation not allowed

And please be sure that the SIM is really inserted properly, if there 
are contact
problems you will get the same result as if no SIM is inserted.

Best regards,

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