Bosch error 0x511001: Acceleration sensor failure in the drive unit
The drive unit has detected a fault in its internal acceleration sensor, the component that measures how hard you are pushing on the pedals and how the bike is moving. As a result the motor switches off its assistance or delays it noticeably, and walk assist is also disabled. The display shows the hex code and the bike effectively becomes a normal unpowered bicycle until the fault is repaired.
| Drive system | Bosch eBike (DiagnosticTool / eBike Flow hex code) |
| Severity | Dealer needed |
| Keep riding? | Do not keep riding |
| Typical cost | Dealer diagnosis usually costs €40-80, and a replacement drive unit is free under warranty, or roughly €600-1200 out of warranty depending on the motor model (Active Line, Performance Line, CX). |
Likely causes
- Internal MEMS acceleration sensor element failed inside the drive unit
- Loose or oxidised connector between the sensor board and the drive unit mainboard
- Moisture ingress into the drive unit housing after washing or riding in heavy rain
- Impact damage to the motor housing from a crash, drop, or transport shock
- Firmware mismatch after a recent Bosch eBike Flow update
How to fix Bosch error 0x511001
- 1. Switch the system off, wait 30 seconds, then switch it back on and check whether the code clears on the next ride.
- 2. Remove and reseat the battery, then clean the battery and motor contacts with a dry cloth before reinserting it.
- 3. Connect the bike to the eBike Flow app or a Bosch DiagnosticTool and read the live fault memory to confirm 0x511001.
- 4. Inspect visible wiring near the drive unit for chafing, crushed sections, or signs of water entry; do not open the motor housing.
- 5. Check whether the error appeared directly after a software update, and if so note the current firmware version for the dealer.
- 6. Take the bike to an authorised Bosch dealer for drive unit diagnosis; if the acceleration sensor is confirmed defective the drive unit must be replaced or internally serviced by the workshop.
Warranty: A genuine internal sensor failure inside the two-year Bosch warranty period is normally covered as a component fault, while water ingress, crash damage, and tampering are excluded.
Typical cost: Dealer diagnosis usually costs €40-80, and a replacement drive unit is free under warranty, or roughly €600-1200 out of warranty depending on the motor model (Active Line, Performance Line, CX).
Frequently asked
Can I reset Bosch error 0x511001?
A power cycle sometimes clears a transient sensor fault, but a confirmed 0x511001 usually returns on the next ride because the sensor itself has failed. A permanent reset is only possible after the dealer has repaired or replaced the drive unit.
Is it safe to keep riding with this code?
No. The motor cuts or delays assistance without warning, which is hazardous in traffic or on climbs. Ride without assistance to the nearest authorised Bosch dealer or arrange collection.
Will Bosch cover this repair under warranty, and what does it cost if not?
If the bike is under two years old and there is no evidence of water damage, crash, or tampering, Bosch treats it as a warranty case and replaces the drive unit at no cost. Out of warranty, budget roughly €700-1100 all-in for diagnosis, parts, and labour on most Performance Line and CX motors.
Related Bosch codes
Manuals and video
- Bosch eBike Help Center: official error-code index
- Bosch eBike downloads: quick start guides and battery guide
- Bosch eBike dealer search (DiagnosticTool readout)
Official source: www.ridewill.com
Not an official Bosch document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.