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 Sensors

W013

Torque sensor initialization failed

The torque sensor could not complete its self-calibration when the system was switched on, most often because a foot was resting on a pedal during startup. Assist is weaker than normal until the sensor is initialized correctly. This is the most common Shimano STEPS warning and is almost always fixed by restarting without pedal load.

Drive system
Shimano STEPS
Category
Sensors
Motor behavior
assist reduced
DIY-friendly?
possible

Roadside self-help

  1. Switch the system off via the battery power button.
  2. Switch it back on without touching the pedals and without load on the crank.
  3. If the warning persists after several clean restarts, contact your dealer.

Possible causes

  • Foot on the pedal while switching the system on high
  • Sensor self-calibration interrupted (vibration, load on crank) medium
  • Persistent torque sensor fault in the drive unit low

Symptoms

  • Assist noticeably weaker than normal
  • W013 appears right after switching on

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • no dealer tool needed
  • 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.