Signal Loss
Dexcom Continuous Glucose Monitor (CGM)
Severity:What Does This Error Mean?
Dexcom G7 Signal Loss means the receiver or phone app has lost Bluetooth communication with the sensor/transmitter. Moving your phone closer to the sensor resolves most signal loss alerts within a minute.
Affected Models
- Dexcom G7
Common Causes
- Phone or receiver is out of Bluetooth range (maximum 6 metres / 20 feet)
- Phone placed in a bag between the sensor and the phone, blocking signal
- Bluetooth turned off on the phone
- Phone in Airplane Mode
- App crashed or running in the background with restricted access
- Sensor in warm-up period — normal for first 30 minutes after insertion
- Sensor placed on a body site with thick tissue between sensor and phone
How to Fix It
-
Bring the phone closer to the sensor.
The Dexcom G7 sensor communicates via Bluetooth with a range of approximately 6 metres (20 feet) in open air. In real-world conditions (through clothing, furniture, your body), the effective range is shorter. Bring your phone to within 1–2 metres of the sensor site for a minute — readings usually resume immediately.
-
Check that Bluetooth is enabled.
On iPhone: swipe down for Control Centre and check the Bluetooth icon is blue (on). On Android: swipe down for Quick Settings and verify Bluetooth is on. If Bluetooth was off, turn it on and wait 30–60 seconds for the app to reconnect automatically.
-
Ensure the Dexcom G7 app has Bluetooth permission.
On iPhone: Settings → Privacy & Security → Bluetooth → check Dexcom G7 is toggled on. On Android: Settings → Apps → Dexcom G7 → Permissions → check Nearby Devices or Bluetooth is allowed. Without Bluetooth permission, the app cannot receive sensor data even when Bluetooth is on.
-
Force close and reopen the app.
On iPhone: swipe up from the bottom and swipe the Dexcom app card away. On Android: tap the recent apps button and swipe the app away. Reopen the Dexcom G7 app. The app will attempt to reconnect to the sensor automatically within 30–60 seconds.
-
Restart the phone.
A full phone restart clears Bluetooth stack issues that prevent reconnection. After restart, open the Dexcom G7 app and wait up to 3 minutes for readings to resume. Do not restart the phone repeatedly — each restart requires Bluetooth to re-scan and reconnect.
Frequently Asked Questions
What happens to my glucose readings during Dexcom G7 signal loss?
During signal loss, readings are not displayed in the app or receiver. The Dexcom G7 sensor continues measuring glucose internally — when signal is restored, the app displays the current reading but does not backfill the missed readings. Alarms (high/low glucose alerts) also do not sound during signal loss, so if you are dependent on alarms, restore the signal quickly by bringing your phone close to the sensor. Always use a fingerstick blood glucose meter to check your glucose during extended signal loss.