I had to deactivate the PIN on a SIM card that I used in a 4G modem on Linux to get the modem to work. This is the AT commands that I used from a serial console:

AT
OK
AT+CPIN?
+CPIN: SIM PIN
OK
AT+CPIN=”0123″
OK
AT+CLCK=”SC”,0,”0123″
OK

The 0123 PIN code is a dummy, use your own PIN of course.