Bosch · Communication
423 Bosch error code 423
Connection problem with the battery
Per manufacturer documentation
Note
Bosch classic system (Intuvia/Nyon/Kiox/Purion). Smart System codes differ.
Possible causes
General, component-based causes – not a manufacturer-specific statement.
- Harness/connector fault (break at handlebar, corrosion)
- Incompatible component/firmware
- Component supply fault
Safe test steps
- Unplug connectors, check pins and corrosion.
- Compatibility (protocol UART/CAN, firmware).
Workshop reference values
- Voltages on communication lines depend on the protocol; measure only with the manufacturer pinout.
Repair approach
- Repair harness/connector; use compatible component/firmware.
Tools needed
- Digital multimeter (CAT III, fused inputs)
- Contact cleaner, dielectric grease
- Manufacturer dealer diagnostic tool/software (if available)
Safety
- Power down (remove the battery) before unplugging connectors. Never apply pack voltage to data wires.
This information does not replace manufacturer service documentation. Work on batteries and high-voltage parts only with the appropriate expertise.