Shimano STEPS error E020: Communication fault between battery and drive unit
The drive unit has lost its data link with the battery and reports a communication error to the display. Motor assist and walk assist are switched off until the link is restored, and the bike behaves like an unpowered bicycle with no support on the pedals. The system holds E020 on the screen until it sees a clean handshake between the two units.
| Drive system | Shimano STEPS (E5000, E6100, E7000, E8000, EP6, EP801) |
| Severity | Fix at home |
| Keep riding? | Do not keep riding |
| Typical cost | A dealer diagnostic with harness check usually runs 40 to 80 EUR, harness replacement 60 to 180 EUR depending on frame routing, and a new genuine battery 450 to 900 EUR if the battery itself is the cause. |
Likely causes
- Battery not fully clicked into the cradle, breaking the data pins at the mount
- Loose or unseated cable between the battery and the drive unit at either connector
- Corroded, wet or contaminated pins in the battery or motor harness
- Bent or partially pushed-in pin on the communication lead
- Damaged cable from crash impact, frame flex or poor routing against the seat tube
- Water ingress into one of the connectors after rain, jet-washing or a deep puddle
How to fix Shimano STEPS error E020
- Switch the system off and remove the battery from the frame.
- Inspect both ends of the battery-to-drive-unit harness for bent pins, green corrosion, moisture or grime.
- Clean any dirty pins with isopropyl alcohol and a lint-free cloth, then let the connectors dry fully.
- Reseat the harness at both ends, making sure the connector is fully home and any collar or locking tab is engaged.
- Refit the battery and confirm it latches with a positive click so the cradle pins are not the weak link.
- Power the bike on and ride briefly to confirm E020 has cleared.
- If E020 returns, book the bike in at an authorised Shimano dealer for a diagnostic with E-Tube Project, because a deeper harness, connector or battery fault needs the dealer tools to confirm.
Warranty: A genuine Shimano component failure inside the two-year warranty period is normally covered, while water ingress, crash damage, cable strain from aftermarket routing and general wear are excluded.
Typical cost: A dealer diagnostic with harness check usually runs 40 to 80 EUR, harness replacement 60 to 180 EUR depending on frame routing, and a new genuine battery 450 to 900 EUR if the battery itself is the cause.
Frequently asked
Can I reset shimano error E020?
Switch the system off, remove the battery, reseat the harness at both ends and refit the battery before powering on again. If E020 comes back straight away, a dealer diagnostic is required because the controller has flagged a persistent communication fault. There is no hidden override that bypasses this code.
Is it safe to keep riding with E020?
No, the motor cuts out and the bike behaves like a heavy unpowered bicycle with no walk assist. Riding with the error active can mask a real wiring fault and risks stranding you mid-ride, so resolve it before the next trip.
How much will the repair cost and is it under warranty?
A simple reseat costs nothing, a dealer diagnostic runs 40 to 80 EUR and a harness replacement 60 to 180 EUR, while a new battery can reach 450 to 900 EUR. Genuine Shimano component faults in the first two years are normally covered by warranty, but water ingress, crash damage and worn parts are not.
Related Shimano STEPS codes
Manuals and video
Official source: si.shimano.com
Not an official Shimano STEPS document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.