I purchased my bicycle with a GRX DI2 1x11v groupset.

Since the bike had an operational left lever, I bought a cable and connected it to the system so I can change the rear derailleur with either hand. I also purchased the wireless module EW-WU111A so I can manage my head-unit from the buttons of the shifters. I used the E-tube project, which recognized everything perfectly, to configure what I wanted to do and it worked great until last week.

Now, for some reason the left shifter has stop working properly. The two levers to shift up/down don't do anything (The top button continues to work fine).

I connected the bike to my computer and the E-Tube project detects everything fine and does not report any problems. I verified the cables and connectors, and everything looks fine.

I have no more ideas to troubleshoot the shifter. Does any of you had similar problems, have any solutions, or ideas to troubleshoot it ?

Thank you!

  • I have exactly the same problem. It’s definitely not cables because if you swap the shifters is over and connect the right to the left and the left to the right the problem persists with the original left shifter. It is definitely configurable because I’ve done it on another bike we have but I just can’t sort it out with this bike. Did you get an answer?
    – Simon
    Jun 29, 2022 at 12:47
  • 1
    Did you update any software/firmware in the meanwhile? It wouldn’t be the first time features are removed
    – Noise
    Jun 30, 2022 at 21:59

3 Answers 3


Sudden problems with Di2 (ie not after a component or software change) very often relate to the connection between the shifter and the wire where forces from the hand might be twisting it around or otherwise stressing it. If you're out of ideas, you could try replacing the wire between the shifter and junction box and see what happens.


I'm not familiar with this fancy new tech, but can you swap cables/ports around to see if the issue stays with the port, or follows the shifter to a different port? A careful process of elimination should show if one part or cable is faulting.

Also remember to look for stains, corrosion, and physical damage which can indicate a failed part or a weak link. You can clean plugs and sockets with contact cleaner, or something like Isopropyl Alcohol to improve connection.


I have had this issues for a year now and here is my take: I have noticed that the shifter only fails when the temperature is high. Yes, you read that correctly. I have no other explanation since the shifter works properly on colder days. I was wondering if someone else can relate the problem to the heat too. Thanks

  • Hi, welcome to bicycles! Since you don't suggest an answer to the question, and indeed you have a problem that may or may not be related, it would be better if you asked a question of your own; that way you can get answers specific to the problem you're having. You might want to take the tour to learn how to use the site effectively.
    – DavidW
    Jul 19, 2022 at 16:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.