Bosch error 424: Communication error between components
The components on the Bosch CAN bus (drive unit, display, battery, remote) are not talking to each other reliably. Assistance may drop out, the display may restart, or the system may refuse to start. Loose or wet connectors cause most cases.
Likely causes
- A plug somewhere in the harness is loose or not locked
- Water or corrosion in a connector after rain or washing
- A damaged cable in the frame, often near the head tube or under the motor cover
- Software versions of the components no longer match after a partial update
- One component (often the display) is failing intermittently
How to fix Bosch error 424
- Switch off, remove and refit the battery, switch on again
- Reseat the display on its holder and clean the contacts
- Check every accessible plug: remote, display cable, light connectors; push each home and lock it
- Let the bike dry indoors if it has been in heavy rain or washed recently
- Restart and see whether the code returns during a short test ride
- If it persists or returns intermittently, a dealer must trace the harness and check software versions with DiagnosticTool
Warranty: Dirty contacts, damaged cables and water ingress are treated as wear or user damage and are rarely covered; a genuine component fault within the 2-year warranty normally is.
Typical cost: Cables and connectors 20-80 EUR/USD plus labour; if a display or drive unit is at fault, 150-1000 EUR/USD depending on the part.
Frequently asked
Can I reset Bosch error 424 myself?
A restart clears the code, and it stays away if the cause was a momentary connector glitch. If it comes back, it is a hardware or software issue that needs a dealer.
Can I keep riding with error 424?
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 424 covered by warranty?
Dirty contacts, damaged cables and water ingress are treated as wear or user damage and are rarely covered; a genuine component fault within the 2-year warranty normally is.
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.