Error code (E-1, E 1, Error 1)
The meter could not produce a result, or found a fault with the strip, the sample, the temperature or itself. The number says which, but only in that maker’s own table: E-3 or Error 3 means something different on every make.
Check your meter’s manual — makers differ.
What it is for
Find the code in the table for your make below, or in your meter’s manual. Most codes are fixed by testing again with a new strip. Accu-Chek (Roche) warns: “Never make therapy decisions based on an error message.”
These pages report what each maker’s manual says and quote it wherever health is involved. They do not diagnose anything, they are not medical advice, and they never tell you how to treat a result; only your own meter’s manual and your healthcare team can do that for your model.
- What it looks like
- The letter E, or the word Error, with a number, shown instead of a result. Accu-Chek writes E-3, Contour E 3, OneTouch and FreeStyle Error 3; the Accu-Chek Guide also shows a circled cross, and the Contour Next One an E symbol.
- Names makers use
- E-1 to E-14 (Accu-Chek Guide); Error 1 to Error 5 (OneTouch Verio Reflect and Verio Flex); E1 to E99 (Contour Next One); Error 1 to Error 4 (FreeStyle Freedom Lite)
Where makes differ
The numbers do not line up between makers. Error 3 is a sample applied too early on OneTouch meters, E 3 is a strip inserted upside down on the Contour Next One, E-3 is a meter or strip error on the Accu-Chek Guide, and Error 3 on the FreeStyle Freedom Lite is an incorrect test procedure. Two makers list a possible very high glucose behind a code: Roche says an E-3 “may indicate that your blood glucose is extremely high and above the system’s measuring range”, and Abbott lists “Very high glucose (above 500 mg/dL or 27.8 mmol/L)” among the causes of FreeStyle Error 2 and “Very low blood glucose (less than 20 mg/dL or 1.1 mmol/L)” among the causes of Error 1.
The codes, maker by maker
| Code | What it means | What to do |
|---|---|---|
| E-1 | “The test strip may be damaged, not properly inserted, or was previously used.” | “Remove and reinsert the test strip or replace it if damaged or previously used.” |
| E-3 | “a meter or a test strip error has occurred. In rare cases, an E-3 message may indicate that your blood glucose is extremely high and above the system’s measuring range.” It can also follow a strip container left open. | Roche (Accu-Chek Guide manual): “Repeat the blood glucose test. If a second E-3 error message appears, perform a control test with the control solution and a new test strip.” If it persists, use a back-up meter; the Roche manual says that if the alternate method “gives an extremely high blood glucose result, or if an alternate method is not available, contact your healthcare professional immediately.” |
| E-4 | “Not enough blood or control solution was drawn into the test strip for measurement or was applied after the test had started.” | “Discard the test strip and repeat the blood glucose or control test.” |
| E-6 | “Blood or control solution was applied to the test strip before Apply drop appeared.” | “Discard the test strip and repeat the blood glucose or control test.” |
| E-7 | “An electronic error occurred.” | Take the batteries out, hold the Power/Set/OK button for at least 2 seconds, put them back and test again. |
| E-8 | “The temperature is above or below the proper range for the system.” | Move somewhere within the range printed on the test strip insert and test again. “Do not artificially heat or cool the meter.” |
| E-9 | “The batteries may be out of power.” | Turn the meter back on; if cold, move somewhere warmer; if it keeps appearing, replace the batteries. |
| E-10 | “The time and date setting may be incorrect.” | Check and correct the time and date. |
| E-11 | “The test strip may be damaged.” | “Retest with a new test strip.” |
| E-12 | “Your blood sample may contain a high level of ascorbate.” | Roche’s page: “Contact your healthcare professional.” |
| E-13 | “Fluid or foreign material may be present in the test strip slot.” | Reinsert the strip or test again with a new one; if it persists, contact Accu-Chek Customer Care. |
| E-14 | “An electronic error has occurred.” | “Contact Accu-Chek Customer Care.” |
| Code | What it means | What to do |
|---|---|---|
| Error 1 | “There is a problem with the meter.” | “Do Not use the meter. Contact Customer Service.” |
| Error 2 | “could be caused by a used test strip, applying blood to the test strip before inserting it into the meter or a problem with the meter or test strip.” | “Repeat the test with a new test strip.” |
| Error 3 | “The sample was applied before the meter was ready.” | Repeat with a new strip, applying the sample only after the Apply Blood or Apply Control Solution screen appears. |
| Error 4 | Not enough blood or control solution, blood added after the countdown began, a strip damaged or moved, or a meter problem (“Strip fill problem”). | “Repeat the test with a new test strip.” |
| Error 5 | “The meter has detected a problem with the test strip. Possible cause is test strip damage.” | “Repeat the test with a new test strip.” |
| Code | What it means | What to do |
|---|---|---|
| E 1 | Too little blood | “Remove the strip. Repeat the test with a new strip.” |
| E 2 | Used test strip | “Remove the strip. Repeat the test with a new strip.” |
| E 3 | Strip upside down | “Remove the strip and insert it correctly.” |
| E 4 | Wrong strip inserted | Repeat the test with a CONTOUR NEXT test strip. |
| E 6 | Moisture damaged strip | “Remove the strip. Repeat the test with a new strip.” |
| E 8 | Strip or test errors | Repeat with a new strip; if it persists, contact Customer Service. |
| E20 | Testing error | Repeat with a new strip; if it persists, contact Customer Service. |
| E24 / E25 | Too cold / too hot to test control solution | Move the meter, strip and control solution somewhere warmer or cooler. “Test in 20 minutes.” |
| E27 / E28 | Too cold / too hot to test | Move the meter and strip somewhere warmer or cooler. “Test in 20 minutes.” |
| E30–E99 | “Meter software or hardware malfunctioned” | Turn the meter off and on again; if it persists, contact Customer Service. |
| Code | What it means | What to do |
|---|---|---|
| Error 1 | Sample too small, a strip or meter problem, or “Very low blood glucose (less than 20 mg/dL or 1.1 mmol/L)”. | Abbott’s booklet: with symptoms such as weakness, sweating, nervousness, headache or confusion, “follow your doctor’s recommendation for treating hypoglycaemia”; then run a control solution test and retest with a new strip. |
| Error 2 | A strip or meter problem, “Very high glucose (above 500 mg/dL or 27.8 mmol/L)”, or HIGH control solution used when too cold. | Abbott’s booklet: with symptoms such as thirst, fatigue, excess urination or blurry vision, “follow your doctor’s recommendation for treating hyperglycaemia”; then run a control solution test and retest with a new strip. |
| Error 3 | “Incorrect test procedure”, for example blood applied before the blood drop and test strip symbols show, or a strip or meter problem. | Wait for the blood drop and test strip symbols, run a control solution test, then retest with a new strip. |
| Error 4 | A problem with the strip or the meter. | Run a control solution test, then retest with a new strip; if it persists, call Customer Care. |
What it does not mean
An error code is not a reading and is not HI or LO. It does not always mean the meter is broken: most codes in these tables are a strip, sample or temperature problem.
Other symbols with the same shapes
HI on the meter (above the measuring range)The letters HI where the number would be, sometimes flashing with…LO on the meter (below the measuring range)The letters LO where the number would be, sometimes flashing with…Thermometer or temperature message (too hot or too cold to test)A small thermometer beside the result on the FreeStyle Freedom…Memory and averages (mem, avg, logbook)The letters mem, or davg with a number of days, on the FreeStyle…
Sources
No published standard we could check defines blood glucose meter control icons, so this meaning is taken from 4 makers’ own manuals and support pages, each fetched and read on the date shown:
- Roche: Accu-Chek Guide blood glucose meter — user manual (US, PDF) — Error Messages chapter: “Never make therapy decisions based on an error message”; the E-3 instructions in full; each message with its cause and what to do. Checked 2026-09-28.
- Roche: Accu-Chek — Guide meter error codes (support pages for E-1 to E-14, HI, LO and the battery icon) — One support page per code for the Accu-Chek Guide: E-1, E-3, E-4, E-6, E-7, E-8, E-9, E-10, E-11, E-12, E-13 and E-14, each with its meaning and what to do. Checked 2026-09-28.
- LifeScan: OneTouch Verio Reflect — owner’s booklet (US, PDF) — Troubleshooting, Error Screens: Error 1 “Meter problem”, Error 2 “Meter or strip problem”, Error 3 “Meter was not ready”, Error 4 “Strip fill problem”, Error 5 “Strip problem”, each with What it means and What to do. Checked 2026-09-28.
- LifeScan: OneTouch Verio Flex — owner’s booklet (US, PDF) — Troubleshooting your system, Error Screens: the same five error meanings, plus an error code in the upper left corner of the screen for Customer Service. Checked 2026-09-28.
- Ascensia: CONTOUR NEXT ONE blood glucose monitoring system — user guide (US, PDF) — Error Detection Displays: “E plus a number”, the meter beeps 2 times; strip errors E1–E8, testing errors E20–E28, system errors E30–E99, each with What It Means and What to Do. Checked 2026-09-28.
- Abbott: FreeStyle Freedom Lite blood glucose monitoring system — owner’s booklet (Australia, ART22410-102 Rev. B, PDF) — System Troubleshooting, Error Messages: Error 1 to Error 4 with Possible Causes and What You Should Do. Checked 2026-09-28.
Written in our own words; quotations are the makers’ wording.