# Ultegra Di2 rear derailleur not working



## pblind (Sep 10, 2011)

So I got a new bike, a Supersix with Ultegra Di2.
The front der is working fine, the rear appears to be dead.

If I go into recovery mode, I see and hear the RD moving - which should mean it has power connected. 
It goes through all the cogs flawlessly.
Is the problem in the shifter? Hard to tell.


Anyone?


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## cxwrench (Nov 9, 2004)

use the plug in-un plug tool and make sure the connector in the shifter is actually plugged in all the way, same at the junction box.


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## pblind (Sep 10, 2011)

Thanks cxwrench. While you wrote your post, I actually unwrapped the bartape and discovered the plug that goes into the shifter wasn't even halfway in. Put it in and wrapped some tape around it. Good to go!


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## iSamurai (May 2, 2012)

*Thanks mate*



cxwrench said:


> use the plug in-un plug tool and make sure the connector in the shifter is actually plugged in all the way, same at the junction box.


Thanks for pointing this out! Just came across this thread having the same problem except with the front derailleur. I realised when I was putting new bar tape on a while ago I had taped down the shifter cable too taut and today the plug has come loose.

I didn't have the connector tool. Used a pair of tweezers instead.

There's also no need to remove bar tape... just roll up the hood and you should be able to access the cable and the port and should just have enough slack to plug it back in.


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