Accu-Chek Performa Nano Owner's Booklet page 70

68
The meter is not
coded or the code
chip is not inserted.
Turn off the meter
and recode it.
The test strips will expire
at the end of the current
month. Before the end of
the month, insert a new
code chip from a new
box of test strips and
ensure the code chip
number matches the
code number on the test strip container.
Make sure the time and date in the meter
are correct.