Furuno Felcom 250 Service Manual page 107

About SIM Cards
SIM cards have 4 passwords; PIN1 code, PUK1 code, PIN2 code, and PUK2 code.
The FELCOM-250/500 does not use PIN2 code and PUK2 code. When you are
requested for the PIN code or the PUK code, enter PIN1 or PUK1.
{
PIN, PUK code
Make sure not to lose the SIM card holder. The PIN code and the PUK code
are described upon the SIM card holder.
If you make erroneous inputs for the PIN code for 3 consecutive times, the
SIM will be locked. If you do not know the PUK code when you release the
locked status of the SIM, you will be unable to restore the SIM to its original
status.
Reference) items stored in the SIM card
Address book: phone numbers
IMSI (International Mobile Subscriber Identity) number
SIM settings: PIN Enable/Disable
PIN Code, PUK Code
URL and phone number for inquiring for services: Displayed upon the "LanchPad"
ICC-ID
SMS (Short Message Service) messages
APN (Access Point Name)
2-3
2.1 SIM Password (PIN Code)