Bosch error 550: Invalid load detected
Bosch BES2 & BES3Fix at homeSafe to keep riding
Something connected to the drive unit's accessory output (lights, USB, a third-party device) is drawing more current than allowed, or there is a short. The motor keeps working but the accessory output is switched off.
Likely causes
- Non-approved or too powerful light fitted
- Short circuit in a light cable or connector
- A USB charger or other device wired to the light output
- Water in a light connector causing a partial short
- Damaged light cable touching the frame
How to fix Bosch error 550
- Switch off the lights in the menu and restart; if the code goes, the problem is on the lighting/accessory circuit
- Disconnect any accessory that is not a Bosch-approved light
- Inspect the light cables and connectors for damage or water
- Reconnect one light at a time to find the offender
- Replace the faulty light or cable with an approved part
- If the code persists with everything disconnected, a dealer should check the drive unit's output
Go to a dealer if: A dealer is needed only when 550 stays with all accessories disconnected, which points to the drive unit's output stage.
Warranty: Damage caused by non-approved accessories is not covered; a spontaneous drive unit fault within warranty is.
Typical cost: Usually free or the price of an approved light (20-80 EUR/USD).
Warranty: Damage caused by non-approved accessories is not covered; a spontaneous drive unit fault within warranty is.
Typical cost: Usually free or the price of an approved light (20-80 EUR/USD).
Still stuck? Take a photo of the display and show it to a local e-bike workshop. Bring the bike's system name (e.g. Bosch Performance Line CX) and the exact code; that saves diagnostic time and money.
Frequently asked
Can I reset Bosch error 550 myself?
Yes. Remove the offending load and restart the system.
Can I keep riding with error 550?
Yes. The drive keeps working normally with this code; it is a warning rather than a safety stop. Get it looked at when convenient, especially if it keeps coming back.
Is error 550 covered by warranty?
Damage caused by non-approved accessories is not covered; a spontaneous drive unit fault within warranty 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.