All Bosch error codes

[Pigin]

Sorry if this has already been posted but here id the list.

 

[Zimmerframe]

A link to also search for any unlisted error codes :

Where can I find out what the various error codes mean?

You can search for specific error codes in the search bar. We provide all codes with a description and steps to a possible solution. Error codes consist of a classifi…

www.bosch-ebike.com

Feel free to add any codes/related fixes in this thread.

@Moderator can you make this a sticky ?

 

[Tony4wd]

I changed the chainring on a Bosch CX4 from 38t to 34t and I get error 503 when I use the lowest gears. Does the dealer have to change a firmware setting when I change chainrings?

 

[Shark58]

Does the dealer have to change a firmware setting when I change chainrings?

Normally not.
Error 503 is a speed sensor fault. I would check the speed sensor cable for correct seating of the plug and the magnet position.

503

Speed sensor fault​

---

Solution steps​

Restart the system. If the problem persists, contact your Bosch eBike dealer.

 

[Tony4wd]

I changed the chainring on a Bosch CX4 from 38t to 34t and I get error 503 when I use the lowest gears. Does the dealer have to change a firmware setting when I change chainrings?

I put the 38t chainring back on and rode the same steep tracks where I was getting 503 errors - problem disappeared so I'm assuming a 4 tooth reduction in chainring size necessitates an alteration in the firmware (I'll ask next time I'm at the shop).
The walk function was also playing up with the 34t but is fine again today with the 38t.

 

[Shark58]

I put the 38t chainring back on and rode the same steep tracks where I was getting 503 errors - problem disappeared

How old is the bike and/or firmware?

Some years back Bosch had a 1:1 problem. When chainring and cog on the cassette had identical numbers of teeth, then the system would throw an error. This has been solved for some time now.

 

[Tony4wd]

it's a 2021 Cube stereo 120 with original firmware.

 

[Shark58]

it's a 2021 Cube stereo 120 with original firmware.

That came with the CX Gen4 motor (non smart) which is not know for having the 1:1 error.

Newest firmware for that motor is 1.1.5.0 and was available since 2020.

I would see my LBS for fault analysis.

 

[Igors]

smart system error

 

[ridefixer]

Great thread to bookmark. For anyone who wants all Bosch codes available offline without hunting through threads mid-ride, I built a free Android app called RideFixer — covers Bosch, Shimano, Bafang, Yamaha and more. Works completely offline, no ads, no login. RideFixer: E-Bike Error Codes - Apps on Google Play