If your OnTracx sensor won’t connect to the app, try these steps:
Wake up the sensor
Remove it from the clip.
Flip it over and locate the two small pins on the back.
Briefly touch both pins at the same time.
The LED will stay on for one minute—during this time the sensor is available for pairing.
No need to switch it off—it will go into sleep mode automatically.
Check Bluetooth permissions
Make sure the OnTracx app has access to Bluetooth.Disconnect from other devices
The sensor can only connect to one device at a time. Disconnect it from any other phone before reconnecting.Reset the sensor
Remove the battery, then place it back in.Check the battery
If the battery is empty, replace it (see battery replacement guide).Restart Bluetooth & apps
Close all apps (including OnTracx), turn Bluetooth off and on again, and disconnect your phone from other Bluetooth devices.Turn on GPS (Android)
On some Android devices, the sensor won’t appear unless GPS is active.
⚠️ Do not pair the sensor in your phone’s Bluetooth settings. This will block it from connecting to the OnTracx app.