How do I fix a Dexcom G7 Sensor Failed notification?
Answer
Note when the failure happened and any extra error text, then follow Dexcom’s official Sensor Failed steps: check the sensor session in the Dexcom G7 app, restart the phone Bluetooth connection, and replace the sensor if Dexcom instructs you to end the session. This is device troubleshooting only, not medical advice.
Before you start: stop right away if…
- This is product troubleshooting only and is not medical advice. Follow your clinician’s plan for glucose monitoring if the sensor fails.
Follow these steps
Capture the alert details
In the Dexcom G7 app, open the Sensor Failed alert and note the full wording, time, and whether any other error code appears with it.
You should see: You have a short written record of the exact Dexcom failure message.
Confirm the sensor session status
Check the app home screen to see whether the current G7 session is still active, warming up, or already ended because of the failure.
You should see: The app clearly shows whether readings have stopped and whether a new sensor is required.
Refresh the phone connection
If the app still seems stuck rather than fully failed, turn Bluetooth off and on, force-close and reopen the Dexcom G7 app, and keep the phone near the sensor for a few minutes.
You should see: Either readings resume, or the Sensor Failed state remains and the app still directs you to replace the sensor.
Follow Dexcom’s replace-sensor path
If Sensor Failed remains, use the in-app End Sensor / Replace Sensor flow only as Dexcom shows it, then start a new G7 sensor with a new applicator per the on-screen steps.
You should see: The failed session ends cleanly and a new sensor warmup or pairing sequence begins.
Contact Dexcom support if failures repeat
If a new sensor fails quickly again, contact Dexcom support with the alert times and any codes; ask about replacement policy rather than repeatedly restarting failed sessions.
You should see: You have next steps from Dexcom for a defective sensor or account replacement request.
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Extra tips
What to look for: The exact Sensor Failed notification, whether it appeared right after starting a new sensor or after hours of use, and any additional Dexcom error codes in the app
Before you change anything: Use only the official Dexcom G7 app from the App Store or Google Play. Write down the alert wording and time before ending a sensor session. Have a backup glucose testing method available if your clinician recommended one. This guide is not medical advice and does not replace your care plan. Never share Dexcom account passwords with unexpected callers.