2007 R1200 GS ABS codes

[Beemer172]

I am getting the following codes and any help in correcting them would be greatly appreciated.  10220 - CAN-bus timeout: no communication with ABS control unit, 41755 CAN-bus timeout to ABS control module, 37649 CAN-bus timeout: no communications with ABS control unit, and 37650 CAN-bus error: Faulty speed signal.

Background:  I was getting the bike out after winter storage (on battery tender all winter) and found the battery dead.  Tried to jumpstart with no luck.  Replaced the battery and started fine.  Speedo didn't register and "brake failure" stayed on.  Put on GS911 and found these codes.  I pulled the rear speed sensor and found nothing apparent...  Quick look at exposed wires and nothing noted.

Is there a way that I can test the ABS unit to see if it s bad?  Any other likely suspects?

[GS Jim]

Don't know what all the codes mean exactly but you can go to real time values and spin the wheel and see if you get a reading from the sensor.
Have you tried resetting the codes and see if they pop up again?
If you aren't using a canbus charger you should disconnect or remove battery while charging just to be on the safe side.

[Beemer172]

i did try to clear the codes without success. I haven't tried spinning the wheel while on the stand, will try that...

I've been lucky with the charger the last 9 or ten years, but it may have caught up with me

Thanks for the ideas