Bosch error 500: Internal fault in the drive unit
The most common serious Bosch code: the drive unit has detected an internal error. Assistance typically stops or becomes intermittent. It can be a one-off glitch, but a repeating 500 usually means the motor's electronics, sensors or windings are at fault.
Likely causes
- Internal electronics or controller board fault in the drive unit
- Water inside the motor housing after pressure washing, river crossings or a very wet winter
- Loose or corroded connector on the drive unit side of the harness
- Overheating followed by a fault on cool-down
- Bearing or gear damage inside the motor causing sensor errors
How to fix Bosch error 500
- Switch off, remove the battery, wait a minute, refit and restart
- If the motor has been very wet, let the bike dry indoors for a day or two before testing
- Check that the drive unit connectors are clean, dry and locked (remove the motor cover if you are comfortable doing so)
- Test ride and note whether the code returns immediately, under load or only when hot
- If it returns, stop riding under assistance and book a dealer: the error memory must be read with DiagnosticTool
- Ask the dealer about a Bosch exchange unit or an independent motor repair if the drive unit is out of warranty
Warranty: Bosch drive units, batteries and displays carry a 2-year manufacturer warranty in most markets; a genuine internal fault within that period is normally replaced free through the dealer.
Typical cost: Out of warranty a drive unit exchange is typically 500-1000 EUR/USD fitted; independent repair (bearings, sensors, board) is often 200-400 EUR/USD.
Frequently asked
Can I reset Bosch error 500 myself?
Restarting is the only user reset and clears a one-off glitch. A recurring 500 cannot be reset away; it needs diagnosis and usually a repair or exchange.
Can I keep riding with error 500?
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 500 covered by warranty?
Bosch drive units, batteries and displays carry a 2-year manufacturer warranty in most markets; a genuine internal fault within that period is normally replaced free through the dealer.
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.