Red Light flashing speed sensor 2

My speed sensor flashes red one time and then does nothing. Perfect new battery doesnt help. Leaving battery out to reset doesnt help. Anyone any idea to fix this? Thank you!

  • Right — same here. So no grounds for a replacement? I’ve had charging issues with FR945 and they replaced it. Was over 1yr old. 

  • Hi, same issue here!

    After a ride my Forerunner 945 tried to update the sensor and now just have the flashing red light.

    Tried new batteries, reset etc.

    Reluctant to buy a new speed sensor as was working perfectly before update.

    Come on Garmin, where are you on this?

  • I had the same issue - the sensor was still on version 2.30 and kept disconnecting and reconnecting every few seconds, with a flashing red light.

    I don't recall initiating a firmware update but today my Edge 530 notified me that a software update (4.10) was available for the sensor. It was a real struggle to apply the update but I managed it and now the connection seems stable and it's not blinking red.

    • Wake the sensor up, be ready with the head unit already in the sensors menu
    • On head unit, go to speed sensor, select about - it should notify about the software update
    • Apply the update... most likely this will stop during the update or fail to connect entirely but use the back button to stay on the software update screen
    • Remove the battery or place in the reverse side (I tried both I don't know which one worked) and leave it for a few minutes
    • Put the battery in, wake the sensor up
    • Wait a few seconds and apply the update

    It took me 5 or 6 tries before the update was actually applied...

    I used the Edge because I had no luck completing the pairing over BT with the phone.

  • Hi kronos,
    i guess your issue was different.
    IMHO when red light blinks every 10 secs seems to be a fatal one.
    You can't communicate with the sensor anymore and so this can't be fixed with any update, just like Ivica Angjeleski described.

    Pretty strange that it can even happen.
    Because risk for wireless fw update is so high... there should be some fallback/plan B.

    ANYHOW, Garmin should replace all such bricked speed sensors regardless they are out of warranty already.
    Simply because it's clearly their fault and destroyed fully functional sensor with the official update.

    BTW, battery is drained in this situation like ***.
    Fresh battery is dead in 24 hours for sure.

    GARMIN, please, it requires clear statement here!!

  • My Edge 840 shows "Sensor Details" but not "About" and under details, there is no software option.  Same with the 820.  Oddly, something connected to it because my phone's connect program states the battery was just check a few minutes ago as "ok"

  • Garmin had absolutely no interest in it when I reported mine. Basically told "it's out of warranty, buy a new one."