Electric bike: Shimano W010 and Bosch 503006 errors, motor overheating

While the thermometer was approaching 40°C, we encountered a W010 error on our bike equipped with a Shimano Steps E6000 motor. This error is not reserved for Shimano since it is also found under the code name “503006” at Bosch. These codes mean that the sensor detects engine overheating and then cuts assistance until a lower temperature returns. This error happens only very rarely, even in very hot weather. In fact, it occurs when the engine is used to the maximum for several tens of minutes. Typically, during a very steep climb, the assistance set to maximum with a high outside temperature and the sun present. The heat from the tar also contributes to the temperature rise of the crankset motor.

What solutions against overheating?

On the Shimano motor, the assistance simply cuts out and the screen displays the error code W010. If you’re on the flat, you can keep pedaling at calf strength, allowing the wind to cool the engine block. Assistance then resumes as soon as the temperature drops. Uphill is more complicated. It is better to stop and wait for the temperature to drop. Putting the bike in the shade also contributes to accelerating the cooling of the block. If this mishap happens to you, don’t panic. Nothing is broken and the appearance of this error is even a good thing since it means that the temperature probe is working correctly and that there is no risk of overheating.

Remember that this problem is quite rare since the motor of an electric bike is never used to the maximum on the flat. From 24 km/h, the engine delivers much less power and, as required by law, from 25 km/h, it simply stops working. To avoid any problems when it’s really hot, you can also choose a less powerful assistance mode (Normal from Shimano or Tour from Bosch, for example), which limits the rise in engine temperature.