Bosch error 431: Software version error
The software versions of the system components do not fit together. This shows up after one part has been updated or replaced without the others. Assistance may be limited until a dealer brings everything to matching versions.
Likely causes
- Display or drive unit replaced with a unit running different firmware
- Interrupted or partial software update at the dealer
- Second-hand component fitted from another bike
- New battery generation fitted to an older system
How to fix Bosch error 431
- Restart the system once to rule out a start-up glitch
- If you recently changed a component yourself, refit the original and test
- Book a dealer visit for a software update with DiagnosticTool; there is no user-side update path on BES2
Warranty: If it follows a dealer job it is normally fixed free; otherwise it is a small diagnostic charge.
Typical cost: Typically a 30-60 EUR/USD software session, no parts.
Frequently asked
Can I reset Bosch error 431 myself?
No. Only the Bosch DiagnosticTool can update firmware on BES2 systems; a restart does not change software versions.
Can I keep riding with error 431?
Usually, but with reduced or interrupted assistance and the risk of the system shutting down mid-ride. Ride home carefully or on muscle power alone; do not plan long rides until the cause is found.
Is error 431 covered by warranty?
If it follows a dealer job it is normally fixed free; otherwise it is a small diagnostic charge.
Related Bosch codes
Not an official Bosch document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.