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Issues with Di2

I picked up a used bike (Ultegra 11-spd) yesterday. When I test-rode it, it was all running well. I got home, took it for a 5-minute spin, and it was fine. But later in the day, I took it out for another ride and the gears wouldn't work any more. 

I left the Di2 on charge all night, but it's still the same. 

When I charge it, there is a red light on the charger that stays red for 5 seconds, then goes off. There is also a little box behind the seatpost (where the charging cable plugs into) and when I press a button there, two lights flash: one red, one green.

The cables to the derailleurs all seem to be fine. I can't see where they connect to the shifters though. 

This is my first experience of Di2. I have absolutely no idea about this stuff. 

Has anyone else had a similar experience? I'm hoping to be able to fix this myself rather than have to take it to a bike shop tomorrow. 

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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10 comments

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IanMSpencer | 8 months ago
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I'd think it was unlikely to be a failed battery unless it's been swimming. My Ultegra is 2016, been used year round with reasonable mileage and I still get months out of each charge.

The Shimano dealer manuals are readily available on the web* which will tell you what to press to check things. You can also download eTube software and attach a PC to Di2 and do some diagnostics.

It will explain the anti-crash reset, as mentioned elsewhere, as well as how to check the battery.

From what you've said, it sounds like something has come loose or has gone into crash mode. The little tool to check the seating of cables is only simple, but to get the cables home needs a lot of pressure, so is pretty much mandatory for Di2 if you don't want to mess things up.

*Though navigating to the right manual can be fun.

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JMcL_Ireland replied to IanMSpencer | 8 months ago
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There's also an E-Tube mobile app which will connect to Di2 over  Bluetooth. I'll add a caveat that I believe not all Di2 controllers come BT enabled with the BT module extra, but since the OP says it's 11 speed Ultegra, they might be good to go.

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hawkinspeter replied to JMcL_Ireland | 8 months ago
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JMcL_Ireland wrote:

There's also an E-Tube mobile app which will connect to Di2 over  Bluetooth. I'll add a caveat that I believe not all Di2 controllers come BT enabled with the BT module extra, but since the OP says it's 11 speed Ultegra, they might be good to go.

Unlikely - most 11 speed Ultegra bikes won't include the bluetooth. They're easy to add though, either through a small "pass-through" one that can sit in the seat tube under the battery or I fitted an MT-800 combination handlebar gear display and bluetooth module.

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Rendel Harris | 8 months ago
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Check it's not gone into crash mode, if the RD gets a bump (even sometimes an innocuous one) it can think it's in a crash so it inboards the derailleur and disengages the motor to prevent further damage. Put the bike on a stand or otherwise hold the back wheel off the ground and hold the button on the control box for about five seconds until you get a flashing red light, at the same time turning the pedals. If it has gone into crash mode it will reconnect after a few seconds and start cycling through the gears.

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Richbeck | 8 months ago
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+1 for bettershifting.com - as a recent Di2 user, this is a VERY comprehensive resource.

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Cugel | 8 months ago
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To check the level of battery charge, you need to press and hold one of the brifter change-gear buttons/levers for at least half a second. Pressing the button on the junction box, as you seem to be doing, puts the changers in adjustment mode or (if pressed longer) reset mode. It doesn't check the battery.

https://bettershifting.com/frequently-asked-questions/how-do-i-check-the...

It's worth checking all the Di2 connections if the bike is second-hand but new to you. To make and break the connections you need to use the Shimano special tool as it's very easy to mangle a connection if you try to make it or break it by hand and get the angle of insertion wrong or break a wire when yanking it out.

https://www.amazon.co.uk/SHIMANO-TL-EW02-Tube-Plug-Tool/dp/B00884323M

How old is the battery? They do eventually degrade then go phut, especially if they've been over-discharged, frozen for a long while or otherwise abused. Time and lots of charging cycles also degrades them.

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firmo123 replied to Cugel | 8 months ago
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Thanks Cugel. 

When I press and hold any of the four shifting buttons, nothing happens. No lights come on or flash on the junction box. Should I be doing something differently here? 

I have no idea how old the battery is. I don't have one of those Shimano tube-plug tools either. My plan was to get this bike now and take it on holiday with me later this week, so I might have to get the LBS to take a look at it tomorrow. Starting to regret moving away from mechanical already!

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Cugel replied to firmo123 | 8 months ago
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firmo123 wrote:

Thanks Cugel. 

When I press and hold any of the four shifting buttons, nothing happens. No lights come on or flash on the junction box. Should I be doing something differently here? 

I have no idea how old the battery is. I don't have one of those Shimano tube-plug tools either. My plan was to get this bike now and take it on holiday with me later this week, so I might have to get the LBS to take a look at it tomorrow. Starting to regret moving away from mechanical already!

If there's no light when you press the brifter shifting parts, then the battery is either completely dead or there's a bad connection somewhere. The red light on the charger coming on for 5 secs then no lght showing suggests a bad connection.

As you had the gears working previously, this also  suggests its more likely that its a bad connection somewhere rather than a defunct battery. So, I'd get one of those Shimano connection tools toot sweet and check the wiring by disconnecting and reconnecting all the junctions, perhaps with a drop of anti-damp spray on each one.

It may be that you have a damaged wire.  Have a careful look at all those that are exposed, especially where they might rub on something.

Another common fault is that the wire into something is getting pulled tight when the bike is ridden. For example, I have to wrap some insulation tape around the Di2 wire and the chainstay near where it enters the rear derailleur as otherwise it gets gradually pulled from somewhere in the frame and gradually goes tight. The insulation tape keeps the wire with some slack on the derailleur side so its not pulling at the connection.

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mark1a | 8 months ago
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What USB port do you have the charger plugged into? It needs to be at least 1 amp, so try charging again with a different USB power supply. 

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firmo123 replied to mark1a | 8 months ago
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At first, I was using an iPhone plug, but now I'm trying a 3.1 Amp socket and there is no difference.

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