Glucose Meter E-1 Error — Test Strip Error Fix Guide

What it means

Accu-Chek glucose meter E-1 is the strip error code documented on Accu-Chek's own support pages (accu-chek.com/error-code/guide-me/e-1, accu-chek.com/error-code/e-1).
Accu-Chek's exact description: 'The test strip may be damaged, not properly inserted, or was previously used.'
The meter is rejecting the current test strip because it can't read it correctly.
The fix is to discard the suspect strip, check the strip lot integrity, and retest with a fresh strip.
Almost never a meter fault.

Affected Models

Accu-Chek Active glucose meters
Accu-Chek Aviva and Aviva Plus meters
Accu-Chek Performa and Performa Nano
Accu-Chek Guide and Guide Me
Accu-Chek's documentation: E-1 = strip error (damaged, improperly inserted, or previously used)

Common Causes

Test strip damaged before use (bent, cracked, contact pad scratched)
Test strip not pushed in fully or inserted upside down
Strip was previously used — strips are single-use; reusing one fires E-1 every time
Strip lot expired (check the expiry date on the vial)
Strip exposed to humidity from a vial left open too long

How to Fix It

Discard the suspect strip.

Don't try to clean or straighten a strip that just gave E-1 — strips are single-use and any contamination or damage is permanent.
Throw the strip in your sharps container (with used lancets) or in regular trash if your local rules allow.
Get a fresh strip from the same vial.
Check the strip vial.

Look at the expiry date printed on the vial — strips past expiry frequently cause E-1.
Check the vial's seal: it should snap closed firmly.
If the vial has been left open for hours or more, the strips inside have absorbed moisture from the air and may all fail.
If you see any visual moisture or stickiness on the strips, get a fresh vial.
Insert the new strip correctly.

Accu-Chek strips have a specific orientation — the contact end (the squared/printed end) goes into the meter slot.
The contact end is the wider end on most Accu-Chek strip types.
Push the strip in until you feel it seat firmly — the meter should beep or display its 'ready to test' icon.
If the meter beeps E-1 immediately on insertion, the strip is in upside down or the strip itself is damaged.
Check the meter's strip contacts.

Open the meter (look in the slot where the strip goes) and examine the metal contacts inside.
If you see blood residue, food, or other contamination, gently clean the contacts with a dry soft cloth or compressed air (never water, alcohol, or chemicals — they damage the contacts).
Dirty contacts cause E-1 on healthy strips.
Try strips from a different vial.

If you have a second sealed vial of strips for the same meter, open it and try a fresh strip.
If the new vial's strips work, the old vial was the problem (humidity, age, or damage).
Discard the old vial.
If the new vial's strips also give E-1, the meter is the likely culprit.
Contact Accu-Chek customer care.

If multiple strips from multiple vials all fire E-1, the meter's contacts have failed or the strip-recognition circuit has worn out.
Accu-Chek has a meter replacement program for customers — visit accu-chek.com or call your country's Accu-Chek customer care line.
Many regions offer free meter replacement (you only pay for strips), so don't pay for repair before checking warranty / replacement options.

When to Call a Professional

E-1 doesn't need professional service.
Discard the problem strip and use a fresh one from the same vial.
If E-1 fires on multiple fresh strips from the same vial, the vial itself may be damaged (left open, exposed to humidity) and a new vial is the fix.
If E-1 fires on every strip from a new sealed vial, the meter has a contact issue — Accu-Chek customer care can help.

Frequently Asked Questions

Can I use a previously-tested strip again if the first reading didn't work?

No — and the meter will refuse it.
Accu-Chek strips contain a chemical reagent that reacts once with blood; after that single reaction, the strip is consumed and cannot give an accurate reading even if you try.
The meter detects the prior use and shows E-1.
This is by design and is the same on every brand of blood glucose strip — OneTouch, Contour, FreeStyle, Trividia, all single-use.
Discard used strips and start fresh.
If you find yourself going through many strips, double-check your finger-prick technique to ensure you're getting enough blood on the first try.