nRF9160 tries to perform the initialization of the Subscriber Identity Module (SIM) card automatically when it is powered up and the modem is started. It is recommended that a Universal Integrated Circuit Card (UICC) card is available during production testing to enable the verification of the UICC status after the initialization from the Device Under Test (DUT).
The result of the UICC initialization can be asked with the %XSIM AT command.
The following command example reads the UICC state:
AT%XSIM?
%XSIM: 1 // State = 1, UICC initialization OK
OK
For more information on the %XSIM AT command, see UICC state %XSIM in nRF91 AT Commands Reference Guide.