What is wrong when the code e-4 appears on accu chek?

The error code e-4 on an Accu-Chek blood glucose meter typically indicates a problem with the test strip, such as improper insertion or a damaged strip. It may also suggest that the meter is unable to read the sample properly. To resolve this, check that the strip is correctly placed and not expired or damaged, and try retesting with a new strip. If the issue persists, consult the user manual or contact customer support for assistance.