How to recover from a failed Di2 Wireless firmware update

Updated April 12, 2023 by BetterShifting

Updated content available

I recently published a new and improved page on Wireless Module troubleshooting. I'm not taking this older page down just yet, but do recommend you read the new guide instead - it is much more up to date.

Read the Complete Guide on Wireless Module troubleshooting

The EW-WU111 Wireless Unit is a great piece of kit. It allows you to view Di2 information on your head unit, let your Di2 system control your head unit and lets you change settings and update firmware using the mobile app.

This last part is the tricky bit. While Shimano’s hardware is top-notch, the mobile apps tend to crash while updating your Di2 firmware, resulting in a non-responsive system. Part of this is due to the nature of wireless firmware updates, but it would have been nice of Shimano to show at least some recovery instructions.

Of course you could just decide to never use the mobile apps and not take any risks – but once you get the apps running they are actually pretty nice. Originally the only way to update the EW-WU111 firmware was using the mobile app, causing a lot of crashed systems... At some point Shimano started shipping the EW-WU111 with updated firmware, allowing you to update it using the SM-BCR2 charger.

If you're lucky you have one of the more recent models. If you're unlucky.. you'll have to do the initial update and setup using the mobile app. Don't worry though, recovery is usually easy!

This is what the update failure looks like..

How to perform the initial update as safe as possible

There are a couple of things you can do to reduce the risk of the update crashing on you. Here they are:

  • Make sure all other components are up to date by connecting the bike to e-Tube project (using the charger) and updating them
  • If the e-Tube Mobile app asks you to change the passkey, try to avoid do this. You can click the 'X' or 'cancel' and it should keep the default '000000'. Note that it is recommended to change the default passkey later, after the initial update has succeeded.
  • If you have already changed the passkey, disconnect the e-Tube mobile app and then go to your phone's bluetooth settings. Forget the EW-WU111 / 101 from the known bluetooth device list. If you don't there is a chance the phone cached the old wireless passkey and fails to reconnect halfway through the firmware update process, causing it to fail.

Update failed, bricked your system?

If the mobile app crashes or interrupts its own update-process chances are pretty good it has rendered your system unresponsive, leaving you unable to connect to it via the app or pc and often unable to shift as well.

Shimano’s official fix involves connecting the SM-PCE1 / SM-PCE02 diagnostic units to the crashed component and restoring functionality that way. Since this tool is rather expensive most consumers won’t have this and will be forced to bring their bike to the local bike shop. However, there often is another way to fix your Di2 system.

Restore Di2 system using SM-BCR2 Charger

Yep! The device you use to charge your Di2 system also doubles as a PC linkage device. You can use it to change or back-up settings and also update the firmware for each of your components. This last bit of functionality is what we’ll use to restore your Di2.

This is what I recommend doing:

  • Disconnect the battery
  • Wait for 30-60 seconds
  • Reconnect the battery
  • Use the SM-BCR2/Charger to connect your bike to your computer via USB
  • Use the e-Tube software to restore the firmware on any confused or crashed components.
  • That’s it! You should now be able to use your bike again! Good luck updating the firmware and Ride On!

E-Tube Project 3.4.5, 4.0.4, or V5 / Professional?

If you've not used E-Tube Project before you may be wondering what version to use. There are three versions, and they're all slightly different. Most importantly, V5 / Professional will not work with the charger. That version only works with the SM-PCE02 diagnostics tool.

The older v3.4.5 and v4.0.4 will work just fine, and I have added links to those versions to the Di2 Software and Tools page.

Can't get to the battery?

Some bicycle manufacturers make it really hard to get to the battery. This is usually due to the frame's design or the use of suspension/flexible seatposts or dropper posts. In some of these cases you'll have to remove the bottom bracket to disconnect the battery and that can be a hassle. Maybe you don't own the correct press-fit tools or just don't want to remove the bottom bracket.

So what can you do? The next best thing is to disconnect every component connected to the battery. As Maik points out in the comments below, this is how that works:

  • Disconnect the wire at the rear derailleur
  • Disconnect the wire at the front derailleur

Next you'll disconnect the front of the bike. This is usually connected via a single wire running from the stem/handlebar into the down tube. If your bike has the EW-RS910 bar-end junction installed then it'll probably be connected to the rest of the system using the Y-splitter and either the EW-JC200 inline junction or EW-WU111 Wireless module. Simply disconnect the wire going from the JC200 / WU111 into the down tube.

Do you use the SM-EW90 below-the-stem junction? Then just disconnect the wire running from that to the rest of the bike.

You have now isolated the battery from the rest of the system, effectively disconnecting it. The only thing it is still connected to is the SM-JC41 Junction B, but that is just a dumb four way splitter.


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