On Call GK Dual Error Codes & Troubleshooting Guide: E5, E6, E12, HI/LO & Code Chip Errors
Dr Pramod kumar
The On Call GK Dual Blood Glucose & Ketone Monitoring System can display error messages and warning symbols relating to test strips, sample application, code-chip setup, battery condition, temperature, meter electronics and data transfer.
Because GK Dual performs both blood glucose and blood β-ketone testing, troubleshooting also requires confirming that the correct strip type and correct code information are being used for the test you intend to perform.
This guide covers E5, E6, E12, code-chip problems, strip errors, HI/LO glucose messages, ketone HI, sample problems and meter-not-reading troubleshooting.
For the full system overview: On Call GK Dual Glucose & Ketone Monitor Complete Guide →
On Call GK Dual Troubleshooting: Quick Reference
| Message / Problem | Likely Cause | What to Check |
|---|---|---|
| E-5 | Insufficient sample or late re-dosing | Repeat with enough blood; second drop only within the permitted short window |
| E-6 | Battery too low for further testing | Replace the batteries before retesting |
| E-12 | Data-transfer cable connected while meter is waiting for sample | Disconnect cable, remove strip and restart test |
| --- CODE | No applicable code stored | Insert the correct code chip supplied with the strip box |
| Incorrect code-chip message | Wrong strip/code-chip family | Confirm Chosen/Advanced for glucose or On Call Blood Ketone strips for ketones |
| Strip removed | Strip came out during testing | Repeat with a new strip and leave it fully inserted |
| Sample applied too early | Blood applied before meter was ready | Wait for the blood-drop / strip-ready symbol |
| Used / contaminated strip | Strip unsuitable for testing | Discard and use a fresh strip |
| Temperature warning | Meter outside operating range | Move to a suitable environment and allow meter to stabilise |
| Glucose HI | Above glucose reportable range | Repeat correctly and seek medical advice if confirmed |
| Glucose LO | Below glucose reportable range | Follow medical guidance for possible severe hypoglycaemia |
| Ketone HI | β-ketone above 8.0 mmol/L | Repeat correctly and seek prompt medical advice if confirmed |
On Call GK Dual E5 Error
E-5 is associated with an insufficient sample or a sample application problem caused by adding more blood too late.
The GK Dual instructions allow a second blood drop within approximately 3 seconds when the first drop has been applied but the meter has not started its countdown.
Once the countdown has started, do not add additional blood.
How to troubleshoot E5
- Discard the failed test strip.
- Use a new compatible strip.
- Wait until the meter is ready for the sample.
- Apply enough blood to fill the strip correctly.
- If the countdown does not start, apply a permitted second drop promptly.
- Do not touch or move the strip while the meter is counting down.
On Call GK Dual E6 Error
E-6 means the battery is too low for the meter to continue performing tests.
The GK Dual uses two CR2032 3V coin-cell batteries.
What to do
- Turn the meter off.
- Open the battery compartment.
- Replace both batteries correctly.
- Check date and time after replacement.
- Repeat the test using a new compatible strip.
A blinking battery symbol can appear before E-6 while some testing capacity remains. Replace the batteries promptly rather than waiting for complete discharge.
On Call GK Dual E12 Error
E-12 can occur when the data-transfer cable is connected while a test strip is already inserted and the meter is waiting for sample application.
How to fix E12
- Disconnect the data-transfer cable.
- Remove the test strip.
- Reinsert a suitable fresh strip.
- Restart the glucose or ketone test normally.
GK Dual Shows --- CODE
If the meter displays flashing dashes together with CODE, it indicates that the applicable glucose or ketone code has not been stored.
Insert the code chip supplied with the corresponding strip box.
For glucose:
- A identifies On Call Advanced coding.
- H identifies On Call Chosen coding.
For ketone testing, use the code chip supplied with the On Call Blood Ketone Test Strips.
Incorrect Code Chip
An incorrect code-chip message can occur when the strip and code-chip family do not match.
For GK Dual:
- Glucose → On Call Advanced or On Call Chosen
- β-ketone → On Call Blood Ketone Test Strips
Do not use an On Call Plus or On Call Extra code chip simply because the products carry the On Call name.
For full compatibility guidance:
On Call GK Dual Strip Compatibility Guide →
Damaged or Removed Code Chip
If the code chip is damaged, use a correct replacement associated with the strip supply.
If it is removed during testing, confirm that the chip corresponds to the current strip family and repeat the test.
Never continue testing when the displayed code does not match the strip box, vial or foil pouch.
Meter Will Not Turn On
Check:
- battery installation,
- battery charge,
- strip insertion direction, and
- whether the meter has been exposed to cold conditions.
If the meter has been stored in cold conditions, allow it approximately 30 minutes to reach room temperature before trying again.
Power-On Self-Check Error
If the meter reports a power-on self-check problem:
- Remove the batteries.
- Wait approximately 30 seconds.
- Reinstall them.
- Turn the meter on again.
If the problem persists, stop repeatedly consuming strips and seek technical support.
Internal Calibration Check Error
If the meter reports an internal calibration-check problem:
- Turn the meter off or remove the strip.
- Restart the meter.
- Insert a fresh compatible strip.
- Repeat the test.
Persistent internal errors may indicate a meter problem requiring support.
Test Strip Removed During Testing
If the strip is removed while the test is running, repeat the test using a new strip.
Leave the strip fully inserted until the result is displayed.
Sample Applied Too Early
Do not apply blood immediately after inserting the strip.
Wait until the meter displays the blood-drop / test-strip ready symbol.
Applying blood before the meter is ready can trigger a sample timing error.
Used or Contaminated Test Strip
If the meter detects an unsuitable strip:
- discard it,
- use a new strip,
- check expiry,
- check storage, and
- confirm correct glucose or ketone compatibility.
Do not reuse a glucose or ketone strip.
GK Dual Strip Testing Error
A strip-testing error can occur when:
- the sample is insufficient,
- blood is added incorrectly,
- the strip is touched or moved during countdown,
- the sample is unsuitable, or
- the strip has a condition or storage problem.
Repeat the test with a fresh compatible strip and apply enough sample promptly.
Meter Too Hot or Too Cold
The published GK Dual operating range is approximately 5–45°C.
If the meter is too hot, move it to a cooler suitable environment. If it is too cold, move it to a warmer environment.
Allow the meter to stabilise before retesting.
Glucose HI
For glucose testing, the meter's published reportable range is approximately 10–600 mg/dL.
A glucose HI message indicates a result above the upper reportable limit.
Repeat the test correctly using a fresh compatible glucose strip. If HI is confirmed, seek prompt medical advice.
Glucose LO
A glucose LO message indicates a result below the meter's approximately 10 mg/dL lower reportable limit.
Follow the emergency low-glucose plan provided by your healthcare professional. A repeated LO result or serious symptoms require immediate attention.
Hypo and Hyper Messages
These are configurable glucose threshold warnings.
They appear only during glucose testing and are based on the hypoglycaemia and hyperglycaemia levels set in the meter.
They are different from HI and LO, which relate to the meter's measurement limits.
What Does “Ketone?” Mean?
The Ketone? reminder appears during glucose testing when the measured glucose value is above approximately 300 mg/dL (16.7 mmol/L), when that indicator is enabled.
It is a prompt to consider ketone testing according to the meter instructions and your healthcare plan.
It is not itself a ketone measurement.
Ketone HI
The GK Dual measures blood β-ketones over approximately 0–8.0 mmol/L.
A ketone HI message means the measured value is above 8.0 mmol/L.
Repeat the test correctly to rule out a procedural problem. A repeatedly confirmed ketone HI result requires prompt medical attention.
GK Dual Does Not Recognise the Strip
Check:
- Is the meter definitely On Call GK Dual?
- Is the strip intended for glucose or ketone testing?
- For glucose, is it On Call Chosen or Advanced?
- For ketones, is it On Call Blood Ketone?
- Is the correct code chip installed?
- Does the displayed code match the pack?
- Is the strip inserted correctly?
- Is the strip new, unexpired and undamaged?
Unexpected Glucose or Ketone Result
Check:
- correct strip family,
- code number,
- expiry,
- storage conditions,
- sample size,
- sample application,
- operating temperature, and
- whether a control solution test is appropriate.
Do not make medication or treatment changes solely on the basis of a troubleshooting article.
Frequently Asked Questions
What does E5 mean on On Call GK Dual?
E-5 is associated with insufficient sample or late sample re-dosing.
What does E6 mean?
E-6 means the batteries are too depleted for further testing.
What does E12 mean?
E-12 can occur when the data-transfer cable is connected while a strip is inserted and waiting for sample.
What does --- CODE mean?
No applicable glucose or ketone code is stored. Insert the correct code chip supplied with the strips.
Why does my GK Dual show Ketone?
The reminder can appear during glucose testing above approximately 300 mg/dL when the feature is enabled.
What does ketone HI mean?
The measured β-ketone concentration is above the meter's 8.0 mmol/L reportable range.
Can I use Plus or Extra strips?
No substitution should be assumed. Use Chosen/Advanced for glucose and On Call Blood Ketone strips for ketone testing.
Related GK Dual Guides
- On Call GK Dual Complete Guide
- GK Dual Strip Compatibility Guide
- Glucose vs Ketone Testing Guide
- Ketone Strips Expiry & Storage Guide
- On Call Complete Guide
Shop GK Dual
On Call Blood Ketone Test Strips 25 →
Medical information notice: This guide explains meter messages and troubleshooting for the On Call GK Dual system. It does not diagnose diabetes, hypoglycaemia, hyperglycaemia or diabetic ketoacidosis and does not replace the manufacturer's instructions or medical advice.
Repeated extreme glucose or ketone readings, persistent vomiting, abdominal pain, difficulty breathing, unusual drowsiness, confusion or other serious symptoms require prompt medical assessment.