App Not Connecting
Dexcom Continuous Glucose Monitor (CGM)
Severity:What Does This Error Mean?
If the Dexcom G7 app won't connect to the sensor, the most common causes are a Bluetooth permission issue, the app not being set up for the new sensor, or the phone being out of range. Check Bluetooth permissions first — this is the fastest fix.
Affected Models
- Dexcom G7
Common Causes
- Bluetooth permission not granted to the Dexcom app
- New sensor inserted but pairing not completed in the app
- App cache corrupted
- Phone OS update revoked Bluetooth permissions
- Using the wrong Dexcom app — G6 app will not connect to G7
- Sensor still in 30-minute warm-up period
How to Fix It
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Check Bluetooth permissions.
On iPhone: Settings → Privacy & Security → Bluetooth → ensure Dexcom G7 is toggled on. On Android: Settings → Apps → Dexcom G7 → Permissions → Nearby Devices → Allow. After a phone OS update, these permissions are sometimes reset — this is a very common cause of sudden connection failures.
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Start the sensor pairing process in the app.
When you insert a new Dexcom G7 sensor, you must start the session in the app. Open the Dexcom G7 app → tap the menu → Start Sensor. Enter the code printed on the sensor applicator. The app will pair with the sensor and begin the 30-minute warm-up countdown.
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Ensure only one device is connected.
The Dexcom G7 can connect to two devices simultaneously (e.g. a phone and a receiver). However, if you have previously paired with another phone and that phone is nearby with Bluetooth on, it may hold the second slot. To add a new device, either turn off Bluetooth on the old device or use the app to manage connected devices.
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Clear the app cache.
On Android: Settings → Apps → Dexcom G7 → Storage → Clear Cache. On iPhone, cache clearing requires deleting and reinstalling the app. After clearing cache, reopen the app and re-enter your Dexcom login credentials to reconnect.
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Reinstall the Dexcom G7 app.
If no other fix works, delete the Dexcom G7 app and reinstall it from the App Store or Google Play. Log back in with your Dexcom account. Your historical data is stored in the cloud and will sync back automatically. After reinstalling, complete the sensor pairing process again.
Frequently Asked Questions
Why won't my Dexcom G7 app find the sensor?
The two most common reasons the Dexcom G7 app cannot find the sensor are: Bluetooth permission was not granted (or was reset by a phone update), and the sensor session was not started in the app after insertion. Check Bluetooth permissions in your phone settings, then open the Dexcom G7 app and use Start Sensor to initiate the session. Also make sure your phone is within 6 metres (20 feet) of the sensor.