heart rate sensor doesn't work anymore (WHR version 0.00)

Hi Igor, same problem here. Encountered big problems with 18.22-18.26 including constant reboots, problems with counting the steps, measures the details over night, problems with the WIF & GPS, etc.

I have the problem with the BMW& WHR 0.0.0, and sensor hub with 0.01.
I was in the Beta, then tried to leave, it did not help - back again. 

I followed the steps you provided, went through plenty of reboots, the watch ended up being on 19.12 but still big problems with the sensors. What do you suggest and will the files you provided work on 19.12 to try and fix the sensors?

thanks! 

...will the files you provided on 19.12 work to try and fix the sensors...? - Not anymore.
I will try to patch the firmware files at the link today and change the versioning in them to 19.20, so that they can be detected and loaded into the watch as more current firmware if you already have version 19.12 installed.
I'll post here as soon as I've swapped the archives at the link.

Thanks, much appreciated 

Fixed the firmware version to 19.20, you can check the sensor firmware update by following the instructions on the same link posted earlier here.

Thanks for sharing the successful result of the experiment. It turns out that file number 2 and 17.26 are a useful combination. As soon as the "sick" one appears, I will have to check and adjust the instructions.
Also, be sure to switch off the automatic firmware update in the watch.

Today they brought another broken watch with the same problem, when the sensor firmware version = 0.00, 0.01.

I managed to restore the sensors by a simpler way.

I did not reset and uninstalled the CIQ apps and large regional maps.
1. Disconnected the computer from the internet, unchecked antivirus temporarily (it can take a long time to initiate placed files on the watch before connecting).
2. Connected the watch via cable.
3. Deleted all files from the Garmin/RemoteSW folder (especially if there is 006D856710.gcd).
4. Copied firmware 2 (2 1515-1920_GUPDATE) from the Garmin folder.

And immediately, after the first attempt, the watch resumed flashing the sensors to the current versions. I will correct the instructions.

Thank you so much Igor!!! Thanks to you I was able to solve the problem!

Hello Igor,

I now have the version 19.18 in my watch and I would like to follow your solution, in order to fix the heart rate sensor issue. 

Currently the sensor is working discontinuously in my watch since I updated to the version 18.23 few months ago. Sometimes the sensor is working quite well for days and suddenly it stopped working...very strange). These last days it is working and the BMX is showing "16.1.2" but most likely it will soon come back to 0.0.0 so I would like to install the old watch version, before the problem appeared.

Just a question regarding your fix, may I know in which folder can I find the large regional maps to be uninstalled ? I've checked "CustomMaps" and "MAPTHEMES" but it doesn't seem to be there.

For the CIQ apps, I didn't install applications so it should be good.

Thank you in advance for your help

Afternoon.
All the mapping is in the watch:
My computer\Forerunner 955 Solar\Internal Storage\GARMIN
(for Windows 10/11) in the root of the Garmin folder are files with the extension .img.
Simply move these files to your computer.

Unfortunately it is not possible to revert to an older version of the firmware for our watch, for now. 

Is there an official Garmin representative office in your country?
If yes, the best way out is to first register a correspondence with technical support about this problem (software failure of the sensor when updating) and then offer Garmin to replace your watch with a new model in their representative office.

Hello Philipp, is your watch working perfectly now, since you do the manipulation?