E-bike reference

42 e-bike error codes, explained in plain language.

What does the code on your display mean? Causes, roadside self-help and sources — for Bosch, Shimano STEPS, Yamaha and more. Free and maintained with love for the detail. Enjoy the ride!

Shimano STEPS Battery

E025

Battery does not recognize the drive unit

The battery cannot identify the connected drive unit, so no system functions start. This occurs when a non-genuine drive unit is connected or when the power cord between battery and motor has come loose or is damaged. The dealer verifies that genuine, matching components are connected and inspects the power cord.

Drive system
Shimano STEPS
Category
Battery
Motor behavior
assist off
DIY-friendly?
shop recommended

Roadside self-help

  1. Reseat the battery and restart once.
  2. If the error remains, have the dealer inspect the power cord and component pairing.

Possible causes

  • Power cord between battery and drive unit loose or damaged high
  • Non-genuine drive unit or battery in the system medium

Symptoms

  • System does not start at all
  • Battery LED may flash an error pattern

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • dealer diagnostic tool required
  • Component: battery
  • Component: drive unit
  • Component: power cable

Applies to

Sources

How to read e-bike error codes

Unlike cars (OBD-II), e-bike codes are manufacturer-specific: the same number means something different on a Bosch than on a Shimano system. What matters is always the combination of drive system and code.