Comment 12 for bug 509738

Here the debug output from modem manager:

** Message: Modem /org/freedesktop/ModemManager/Modems/0: state changed (disabled -> enabling)
** (modem-manager:1994): DEBUG: (ttyUSB2): --> 'ATZ E0 V1 +CMEE=1<CR>'
** (modem-manager:1994): DEBUG: (ttyUSB2): <-- '<CR><LF>OK<CR><LF>'
** (modem-manager:1994): DEBUG: (ttyUSB2): --> 'ATE0 +CMEE=1<CR>'
** (modem-manager:1994): DEBUG: (ttyUSB2): <-- '<CR><LF>OK<CR><LF>'
** (modem-manager:1994): DEBUG: (ttyUSB2): --> 'ATX4 &C1<CR>'
** (modem-manager:1994): DEBUG: (ttyUSB2): <-- '<CR><LF>OK<CR><LF>'
** (modem-manager:1994): DEBUG: (ttyUSB2): --> 'AT+CREG=0<CR>'
** (modem-manager:1994): DEBUG: (ttyUSB2): <-- '<CR><LF>ERROR<CR><LF>'
** (modem-manager:1994): DEBUG: Got failure code 100: Unknown error
** (modem-manager:1994): DEBUG: (ttyUSB2): --> 'AT+CFUN=1<CR>'
** (modem-manager:1994): DEBUG: (ttyUSB2): <-- '<CR><LF>OK<CR><LF>'
** Message: Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabling -> enabled)
** (modem-manager:1994): DEBUG: (ttyUSB2): --> 'AT+CPIN?<CR>'
** (modem-manager:1994): DEBUG: (ttyUSB2): <-- '<CR><LF>+CPIN: SIM PIN<CR><LF><CR><LF>OK<CR><LF>'
** Message: Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabled -> disabled)