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 Motor / drive

W012

Crank possibly installed in wrong direction

The system suspects that the crank arms were mounted in the wrong orientation, which distorts the torque measurement. This warning typically appears after assembly or crank service. The crank must be re-installed in the specified direction and the system restarted.

Drive system
Shimano STEPS
Category
Motor / drive
Motor behavior
behavior unclear
DIY-friendly?
shop recommended

Roadside self-help

  1. Restart the system once without any load on the pedals.
  2. If the warning returns, have the crank orientation checked and corrected by a dealer.

Possible causes

  • Crank arm mounted in the wrong direction during assembly high
  • Heavy pedal load at power-on confusing the sensor check medium

Symptoms

  • W012 appears after crank or drivetrain work
  • Assist feels wrong or restricted

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • no dealer tool needed
  • Component: crank arm
  • Component: torque sensor

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.