Accu-Chek E-9 Error — Memory Error Fix

What it means

E-9 means the Accu-Chek meter detected a memory or internal settings error.
This can be caused by a depleted battery corrupting the meter's memory during a power loss, or by a firmware issue.
A battery reset often resolves E-9, but stored test results may be lost.

Affected Models

Accu-Chek Guide
Accu-Chek Aviva
Accu-Chek Performa

How to Fix It

Remove the batteries and wait 60 seconds

Open the battery compartment, remove all batteries, and wait a full 60 seconds.
This is longer than a standard reset — the extended wait ensures that all residual charge drains from the meter's memory circuits before you reinsert the batteries.
Replace with fresh batteries

Do not reinsert the old batteries — if they were low, they may have caused the memory corruption in the first place.
Use a new set of the correct battery type listed in your meter's manual (typically CR2032 for Guide, or two AAA for Aviva).
Reset the date, time, and strip code

After the battery replacement, the meter will ask you to set the date and time again.
Complete the setup.
On meters that require a strip code, re-enter the code from the current strip vial.
Run a control solution test

Before using the meter for a real blood glucose test, run a quality control test using the Accu-Chek control solution.
This confirms the meter is working within the correct range after the reset.
Contact Accu-Chek if E-9 returns

If E-9 returns after a fresh battery installation, the meter's memory chip is likely damaged and the meter needs to be replaced.
Contact Accu-Chek support — replacement is usually free under warranty.

Frequently Asked Questions

Will E-9 delete all my saved test results?

Possibly.
E-9 is a memory fault, and a battery reset to clear it may erase stored results.
If your results are important, note them down before performing the reset.
Going forward, consider using the Accu-Chek Smart app or mySugr to back up readings automatically.