Technical tips · Shimano Di2
Connecting the SM-PCE02 to Di2:
12-speed (SD300) systems
The SM-PCE02 is the tool for advanced diagnostics, firmware updates and battery checks on Shimano Di2. A 12-speed bike needs an SD300 cable or adapter, and here is every place you can plug it in.
By Marko Ristivojević, Master Bike Mechanic
In short
An SM-PCE02 Di2 connection on a 12-speed Shimano system goes through the SD300 port, using a direct cable (Y79M9801T) or the EW-AD305 adapter, and is used for advanced diagnostics and firmware updates in E-Tube Project Professional.
12-speed standard
SD300
SD50 to SD300 adapter
EW-AD305
Direct cable
Y79M9801T
Junction box
EW-JC304 (4 ports)
Author: Marko Ristivojević, Master Bike Mechanic · BK MTB Evolution, East Sarajevo
Why you need the SM-PCE02
12-speed Shimano Di2 systems bring new SD300 ports and a new diagnostic approach. The mobile E-Tube Project app is handy, but for serious diagnostics, software recovery and a detailed check of battery consumption, the SM-PCE02 tool is essential.
The mobile version lacks the advanced features of the E-Tube Project Professional desktop software, and shifter firmware can’t be updated without a wired link. That is why it pays to know how to connect it to the SD300 standard.
Conversion tools: SD50 to SD300
Older SM-PCE02. It most likely came with only an SD50 cable for 11-speed systems, so SD300 needs a hardware conversion.
EW-AD305 adapter. It has an SD50 and an SD300 port. Plug the PCE02’s SD50 cable into one side and a spare EW-SD300 cable into the other, then use that cable to connect to the bike.
Direct SD300 cable (Y79M9801T). A single cable that plugs straight into the SD300 port on the bike. Newer SM-PCE02 units often come with both cables, so no adapter is needed.
Connecting directly to the shifter (firmware update)
When to use it. The quickest route for diagnostics and software updates of individual shifters.
Port access. Carefully push the shifter’s rubber hood back to reveal the SD300 port.
Connecting. Plug the SD300 cable into the upper port.
Important. The lower port is reserved exclusively for satellite shifters.
Connecting through the battery’s third port
When it works well. When the battery is easy to reach (e.g. inside the seatpost) and the bike has disc brakes. The third port is often unused.
Battery access. Pull out the seatpost.
Port. Remove the dummy plug from the battery’s third port.
Connecting. Plug the SM-PCE02 cable in directly.
SM-PCE02 Di2 connection through the rear derailleur (recommended)
What you need. One EW-JC304 four-port junction box and one spare EW-SD300 cable.
Unplug. Disconnect the cable that goes into the rear derailleur.
Connect the box. Plug that original cable into one port of the EW-JC304 box.
Close the circuit. Use the spare EW-SD300 cable to connect the derailleur back to the EW-JC304 box.
PCE02 connection. One free port on the box is now available for plugging in the SM-PCE02 directly.
Why this way. It creates a secure junction at the derailleur that opens a diagnostic port while the system stays fully functional. You can check the whole system: battery, both derailleurs and settings.
Conclusion and E-Tube Project Professional
Software. Once connected, launch E-Tube Project Professional on your computer.
What you can do. Run complete diagnostics, update firmware and fine-tune Synchro Shift.
Download. Get the program from Shimano’s E-Tube Project Professional page.
Pro tip. Before connecting, check whether your SM-PCE02 came with an SD300 cable. If not, get the direct Y79M9801T cable or the EW-AD305 adapter.
SM-PCE02 and Di2 diagnostics FAQ
Is the SM-PCE02 necessary for every Di2 service?
It is not necessary for basic shifting adjustments, but for advanced diagnostics, battery health checks, firmware updates of individual components and system resets after an error, the SM-PCE02 is a must-have tool.
Can I use the older SM-PCE1 device?
Unfortunately, the SM-PCE1 is not fully compatible with the new 12-speed software and the E-Tube Project Professional application for newer generations of parts. For working with the SD300 standard and 12 speeds, the SM-PCE02 is recommended.
What is the difference between the EW-AD305 adapter and the direct cable?
Functionally there is no difference. The EW-AD305 converts the old SD50 cable to the new SD300 standard, while the direct cable (Y79M9801T) is the neater solution because it removes the need for an adapter.
Which shifter port does the SM-PCE02 plug into?
The upper SD300 port, which you reveal by pushing the shifter’s rubber hood back. The lower port is reserved exclusively for satellite shifters.