Freestyle Libre 3 Sensor Errors: Guide to Resolve

Freestyle Libre 3 is an advanced super small, and thin CGM system. Usually worn on the back of your upper arm. And yes, Abbot has reduced plastic use by 41% and carton paper use by 43% during its production – making it more environmental friendly. It boasts an exceptional MARD value of less than 8%.

However, like all medical devices, users may occasionally experience small issues or sensor errors. Below is a complete guide to common Freestyle Libre 3 sensor errors and practical solutions to fix them.

Common FreeStyle Libre 3 Sensor Errors and Solutions

1. Sensor Is Not Sticking Properly

Solution: The reason may be the site is not free of dirt, oil, hair or sweat. Following the steps below may assist:

• Remove the Sensor.
• Clean the site with soap and water.
• Follow the guidelines before applying and starting your Sensor sections

2. Skin Irritation or Redness at Application Site

Problem: Skin irritation or itching under or around the sensor.

Possible Cause: Friction from clothing, accessories, or skin sensitivity to the adhesive.

Solution:

• Avoid tight clothing that rubs the sensor site.
• If irritation persists, contact your healthcare provider.
• They can recommend barrier wipes or hypoallergenic adhesives compatible with CGM sensors.

3. Trouble Starting or Activating a New Sensor

• Problem: The new Libre 3 sensor fails to start or show readings.
• Possible Cause: The sensor requires up to 60 minutes to warm up before glucose readings begin.

Solution:

• Wait for the full 60-minute sensor setup period to complete.
• Do not attempt to scan before that time.

4. Scanning Timeout

• Problem: The Freestyle Libre 3 reader or app fails to scan the sensor.
• Possible Cause: The reader or smartphone is too far from the sensor.

Solution: The reason may be that the Reader is not close enough to the Sensor. Grasp the Reader within 4 cm (1.5 inches) of the Sensor and carry the screen of the Reader near the Sensor.

5. “Sensor Ended” Message

• Problem: The reader shows that the sensor has ended.
• Cause: The 14-day sensor life is complete.

Solution: This may mean the Sensor life has finished. Put on and start a new Sensor.

6. “New Sensor Found” Notification

Problem: The system detects a new sensor before the old one has finished.

Solution: This may mean that before your previous Sensor ended, you scanned a new Sensor. The Reader will only be utilized with one Sensor at a time. If you apply and start a new Sensor, you will no longer be able to scan your old Sensor. If you would like to begin using the new Sensor, select “Yes”.

7. Scanning Error

Problem: The reader fails to communicate with the sensor.

Solution: This may mean that the Reader was unable to communicate with the Sensor. Try scanning again.

8. “Sensor Error” Message

Problem: The system is unable to provide a glucose reading temporarily.

Solution: This may mean that the system is unable to provide a glucose reading at the moment. Try to scan again in 10 minutes.

9. “Glucose Reading Unavailable”

• Problem: The reader displays that glucose readings are unavailable.
• Possible Cause: The sensor temperature is either too hot or too cold.

Solution:

• Move to a moderate temperature area.
• Wait a few minutes before rescanning.

10. “Sensor Already in Use”

Problem: Your sensor was already activated by another reader or smartphone.

Solution:

• Use the same reader or phone that initiated the sensor.
• Otherwise, start and apply a new sensor.

11. “Replace Sensor” Message

• Problem: The reader has detected a problem with your sensor.
• Solution: Remove and replace the sensor with a new one.

Freestyle Libre 3 Reader Errors With Solutions

Even when the sensor is working fine, your Freestyle Libre 3 Reader or smartphone app might encounter issues. Below are common reader-related errors and solutions.

a. Difficulty Receiving Glucose Alarms

Possible Causes & Solutions:

• Alarms are turned off: Go to Settings → Alarms and enable them.
• Sensor not linking: Ensure the reader or smartphone is within 6 meters (20 feet) of the sensor.
• Signal loss: If the Signal Loss Alarm appears again after scanning, contact Abbott Customer Service.
• Sound/vibration off: Check your reader’s sound and vibration settings.

b. Alarms Not Showing on Smartwatch

Solution: If you use the Freestyle Libre 3 app, ensure:

• Alarms are turned on.
• Your smartphone and smartwatch are paired and configured to share notifications.

c. Reader Battery Dead

Solution:

• Charge your reader using the included USB cable.
• Low battery can prevent scanning and alarms from functioning properly.

d. Alarm Signal Loss

Problem: The reader hasn’t received data from the sensor for over 20 minutes.

Solution:

• Keep the reader within 20 feet (6 meters) of the sensor.
• Try scanning again.
• If the problem repeats, contact Abbott Customer Support.

Final Thoughts

Most Freestyle Libre 3 sensor errors are simple to fix — from repositioning your reader to replacing an expired sensor. The system is designed to guide you through many issues directly on your reader or smartphone screen.

If you’ve experienced a unique Freestyle Libre 3 sensor error and found a solution that worked for you, share it in the comments to help others in the community.