Error 21h on BBS01a

[Dewey]

I just got my bike back from the shop after upgrading my gears from a derallieur to an IGH, plugged in the kit and got Error 21h on my C965 display. The speed sensor light is on which suggests its a problem with the speed sensor wire going into the controller. This will be the third time I have replaced the controller since buying the kit in fall 2016, and the second time for an Error 21h malfunction. The controller is potted so I can't solder the wire back onto the circuit board, I tried doing that before and made a real mess trying to dig out the potting compound. I have a version A pre-April 2016 BBS01 so replacement controllers are getting hard to find (California ebike & EM3EV are out of stock). Not ready to cut off the kit for an all new replacement just yet as the motor, PAS & throttle work, I just get Error 21h and no display.

 

[Dewey]

Just realized I may have installed the spoke magnet the wrong way around, will check tonight, hope this fixes the issue as I don't want to spring for another controller.

What got me thinking is I just installed ebrake sensors on my Shimano linear pull brake handles and the tiny magnets were not very powerful requiring me to install the stick on sensor half an inch closer to the magnet.

 

[Dewey]

...it worked! I just had the magnet turned around, so turned it around and the error 21h disappeared. Then I discovered I couldn’t test the motor or use walk assist because one of the ebrake magnets had come unglued and the motor cut out symbol was always on...sigh!

 

[Dewey]

So I bought some 8mmx3mm disk magnets with a hole in the middle from Amazon and threaded 4 of them onto some aluminum wire, twisted around the brake handle and gorilla glued them near the ebrake sensor, and hey presto the motor cut out symbol disappeared and motor and walk assist are working again. Did both sides just to be sure.