Di2 Synchro Shift problem
 

Hi from the UK.

I've lurked here a while but have registered to post a question which I hope somebody can help with.

I have the required hardware for synchro shift and all firmware is up to date. I've been using it (and loving it) for several months now. I recently had to disconnect the battery as I removed the seat post, and on reconnecting I can't get synchro shift to work.

The button on junction box A still works (to set into bluetooth mode or adjust mech trim), but double clicking does not change between shifting modes. Its basically stuck in mode 1 (traditional shifting) which is working fine on both derailleurs, but I can't get it to change into modes 2 or 3.

I'd be very grateful if somebody could come up with a suggestion as to what I have done and how it can be fixed.

Cheers

Cornflake

Things you can try...

Connect it to E-Tube and see if there are any faults, update firmware if needed.

Swap a known good junction from another bike.

Call Shimano. See http://www.shimano.com/en/company/locations.html for phone numbers.