Accu-Chek Aviva Owner's Booklet page 86

The meter is not coded or the code
key is not inserted. Turn off the meter
and recode it. See Chapter 1,
"Coding the Meter."
The test strips expire at the end of
the current month. Before the end of
the month, insert a new code key
from a new box of test strips and
ensure the code key number
matches the code number on the
84
test strip container. Make sure the
time and date in the meter are
correct.
The test strip may be damaged or
the code key is incorrect. Remove
and reinsert the test strip. If the
message reappears, turn off the
meter and insert a new code key.
Make sure the code number on the
code key inserted in the meter
matches the code number on the container of
test strips. If the message reappears contact the
ACCU‑CHEK Customer Care Service Center at
1‑800‑858‑8072.