What Shimano says
Travel speed can't be detected. The speed sensor may be out of position, or the magnet on the brake disc rotor may have come off. The top assisted speed is reduced.
Shimano's recommended steps
- Check that the speed sensor and its magnet on the brake disc rotor are in place.
Summarized from Shimano STEPS E8080 user manual (Japanese, translated) (error W011), checked October 23, 2026. Follow the link for Shimano's exact wording.
If it keeps coming back
If the code comes back after a restart, have it checked by a mechanic who works on Shimano systems. Bikes Plus has diagnostic tools for Shimano and most other major motor systems.
Write down the code and what you were doing when it appeared. That saves time at the shop.
Make sure it's a Shimano code
Error numbers mean different things on different systems. This page covers Shimano STEPS and EP e-bike systems. Codes starting with W are warnings, which clear when conditions improve; codes starting with E are errors, which point to a possible fault. Shimano's E-TUBE PROJECT Cyclist app can read the code from the bike.