EP801 Error E903 Retrofit CUES Di2 on SCOR 4060 Z - Configuration Locked?

[DéraYéh]

Hi everyone,

I am hitting a wall with a Di2 retrofit on a new Gen 2 system and hoping for some technical insight.

The Bike: SCOR 4060 Z (2025 Model) The Motor: Shimano EP801 The Project: Retrofitting CUES Di2 (RD-U6070).

Hardware Setup:

• Derailleur: Shimano CUES Di2 RD-U6070 (LinkGlide)
• Shifter: XT Di2 SW-M8150
• Diagnostics Tool: SM-PCE02 interface
• Software: E-Tube Project Professional V5 (latest version)

The Issue: I have updated all firmwares (Drive Unit, Derailleur, Shifter, Battery) to the latest versions using the PCE02. However, I am stuck with a persistent Error E903 (Fatal System Error).

Troubleshooting steps taken:

1. Isolation: When I disconnect the Di2 derailleur, the motor runs (I get a temporary W292 error because I swapped the rear wheel to a 27.5" mullet setup and need to adjust the magnet, but the system boots up).
2. Connection: As soon as the CUES derailleur is connected, E903 triggers immediately.
3. E-Tube Lock: In E-Tube Project V5 (via PCE02), I am unable to change the "Gear Ratio" or "Drive Train" settings. The software either greys out the option or fails to apply the changes to the Drive Unit. It seems the motor does not want to accept a LinkGlide/Di2 configuration.
4. ST Unlocker: I tried using ST Unlocker. I can seemingly modify the parameters in the app, but after writing and rebooting, the E903 error persists.

My Question: Is it possible that SCOR "factory locked" the Bike Data to "Mechanical shifting only"? Is there a known workaround to force the EP801 to recognize a CUES Di2 component without needing a full OEM "Bike Data" rewrite from a dealer?

Any help would be appreciated. Thanks!

 

[bmwpowere36m3]

Based on posts I've seen related to the 4060z... the EP801 is "locked" by SCOR. I think one user wanted to change his chainring size and the local Shimano dealer couldn't do it. I forget, but they need someone from Shimano directly to "remote in" and the process to get to that point that was long.

I have a 4060z myself, cracked two rear triangles in 3 months... I can't wait to get ride of this POS. SCOR/BMC is not addressing these issues, which are common.

 

[BAh30]

I used a PCE02, my windows 11 PC and the eMAX mini software app to reduce the size of my chainring when i changed it on my kemens ep6. eMAX mini also allows to change the shifting from mechanical to Di2.

 

[Backflip]

Hi everyone,

I am hitting a wall with a Di2 retrofit on a new Gen 2 system and hoping for some technical insight.

The Bike: SCOR 4060 Z (2025 Model) The Motor: Shimano EP801 The Project: Retrofitting CUES Di2 (RD-U6070).

Hardware Setup:

• Derailleur: Shimano CUES Di2 RD-U6070 (LinkGlide)
• Shifter: XT Di2 SW-M8150
• Diagnostics Tool: SM-PCE02 interface
• Software: E-Tube Project Professional V5 (latest version)

The Issue: I have updated all firmwares (Drive Unit, Derailleur, Shifter, Battery) to the latest versions using the PCE02. However, I am stuck with a persistent Error E903 (Fatal System Error).

Troubleshooting steps taken:

1. Isolation: When I disconnect the Di2 derailleur, the motor runs (I get a temporary W292 error because I swapped the rear wheel to a 27.5" mullet setup and need to adjust the magnet, but the system boots up).
2. Connection: As soon as the CUES derailleur is connected, E903 triggers immediately.
3. E-Tube Lock: In E-Tube Project V5 (via PCE02), I am unable to change the "Gear Ratio" or "Drive Train" settings. The software either greys out the option or fails to apply the changes to the Drive Unit. It seems the motor does not want to accept a LinkGlide/Di2 configuration.
4. ST Unlocker: I tried using ST Unlocker. I can seemingly modify the parameters in the app, but after writing and rebooting, the E903 error persists.

My Question: Is it possible that SCOR "factory locked" the Bike Data to "Mechanical shifting only"? Is there a known workaround to force the EP801 to recognize a CUES Di2 component without needing a full OEM "Bike Data" rewrite from a dealer?

Any help would be appreciated. Thanks!

As long as your SCOR 4060 with DU-EP801 uses a real "generation 2" battery (compare page 10 with 11 in this document and check the E-Tube-Project software from Shimano for this), you can use a cable-bound SM-PCE02 interface and the Windows based miniMax - program from eMax-Tuning already in the licence key free (and so free of charge) version to program the correct Di2 derailleur and so avoid the E903. See also chapter 12.2 of this document.
Maybe also this forum post could be helpful.

 

[Astro66]

In summary.

Just get the Minimax software. It's free. Once connected, with in the software is a "Mechanical" or "Electronic" derailleur selection.

Just select electronic. This will clear the 903 error.

 

[cris22]

In summary.

Just get the Minimax software. It's free. Once connected, with in the software is a "Mechanical" or "Electronic" derailleur selection.

Just select electronic. This will clear the 903 error.

View attachment 181034

Do you know if there is any other way to change from manual to electronic without the need of the PCE02?

 

[Backflip]

Do you know if there is any other way to change from manual to electronic without the need of the PCE02?

On a DU-EP500, DU-EP600 and DU-EP801 there is definitely NO way to change the derailleur from manual to electronics (Di2) without the cable bound PCE interface from Shimano (and a Windows based computer as well as the Windows based miniMax - program from eMax-Tuning which can do this job already in the licence key free and so completely free of charge version). There are a lot of clever people who rent this gear on a daily basis on some internet platforms.