The Shimano SM-PCE1 can update the firmware just like the SM-BCR2 internal battery charger but plugs into a spare E-tube port on the shift lever because the PCE1 uses an E-tube interface. The PCE1 has a few more capabilities over the BCR2 in that it can also perform an error check and diagnose potential problems. Because it has an E-tube connection, the PCE1 can update the firmware when the front SM-EW67 A-E wire kit (later replaced by the SM-EW90A & B) is used.

Any complete, modern workshop needs a Di2 system checker to diagnose problems, update firmware and change system settings and functions. Most issues can be fixed by checking connections and updating firmware making certain all your Di2 components are on the same firmware. In the extremely rare event of a defective component, the PCE1will identify the culprit and expedite the warranty process.

The PCE1 differs from the SM-BCR2 battery charger in that it has an E-Tube end that can plug directly in a component without the need to go through the cockpit junction and its microchip. This let you isolate each component for perfect troubleshooting.