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Di2 cutting in and out

Old 01-03-20, 09:49 PM
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melikebikey35
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Di2 cutting in and out

So my ultegra Di2 started to act up today...

It's been working perfectly ever since moving everything over to a new frame last month, but 15 minutes into my ride today, it just stopped shifting. A few minutes later it would work for a moment. Then stopped again...so on and so forth. I just went through the whole system, disconnected and reconnected every wire, but that didn't solve anything. I also noticed that it would randomly go into micro-adjust mode when it is working.

Battery is/was sufficiently charged, and the bike has not been washed/exposed to any harsh weather/conditions recently. The entire system is about six months old and this is the first time that I've experienced an issue. Unfortunately, I only have Mac/iOS (do not have wireless unit installed) at home so I'm not able to connect to the E-Tube software to run diagnostics or update firmware.

Has any one else experienced something similar? Or have any ideas about a solution?
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Old 01-03-20, 10:02 PM
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sanmi
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Loose connection? I had intermittent problems when I first got Di2 and didnít have the little plastic wiring tool. I had plugged a component in by hand and the connection wasnít sufficiently secure.
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Old 01-05-20, 01:26 PM
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TerryDi2C
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The first thing usually happens when there is a loose connection or 'broken' electric wire.

It shouldn't go into micro-adjust mode by itself though.. If I had to guess I'd blame the Junction A, but that'd just be guessing . I would take it to an LBS so that they can hook it up to an SM-PCE02 (or SM-PCE1) to do diagnostics.
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Old 01-05-20, 05:51 PM
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melikebikey35
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I did take it to my LBS yesterday, and they hooked it up to the diagnostic software. No errors came up, but every component was due for a firmware update. After the update it was back to shifting normally...for a brief time. Once I got it home, it started acting up again. I then tried replacing the battery, but that did not solve it. So, I ordered new A and B junction boxes, Y-split/down tube wires. Once they arrive, I'll tear down the whole system and start replacing components until it works again.

After thinking about for a while, I believe that it's the down tube wire that's the cause...I have it heat-shrinked to the brake hose and where they enter the frame is a very tight fit (Di2 isn't designed to go there on an R5).
I then tried a longer stem for a few days earlier in the week, so I think that may have stretched/pinched the Di2 wire, since there wasn't enough slack.
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Old 01-05-20, 09:47 PM
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melikebikey35
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UPDATE: I was right...it was the downtube wire. I put a new one in and everything seems to be back to normal
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