Brose error 42: Internal motor rotation sensor fault
The Brose drive has detected an internal fault in motor rotation, meaning the controller cannot confirm the motor is spinning the way the torque and cadence sensors expect. Motor assist is cut immediately and the display will show the code instead of normal ride data. Walk assist and pedal support remain disabled until the fault clears.
| Drive system | Brose Drive (S, T, C - also used by Bulls, Rotwild, Fantic, BH, Trek Allant) |
| Severity | Dealer needed |
| Keep riding? | Do not keep riding |
| Typical cost | Dealer diagnostics typically run EUR 40 to EUR 80, a Hall sensor or motor service repair around EUR 120 to EUR 250, and a complete motor replacement usually EUR 500 to EUR 900 depending on the Brose model. |
Likely causes
- Damaged or contaminated Hall sensor inside the motor
- Loose or corroded motor cable connector at the motor housing or frame junction
- Frayed motor cable where it exits the motor and enters the frame
- Water or mud ingress into the motor housing after a deep water crossing or pressure wash
- Internal motor winding or stator fault requiring motor replacement
- Outdated or corrupted motor firmware after a recent update
How to fix Brose error 42
- Stop riding and switch off the system using the control panel button.
- Wait at least 30 seconds to allow the drive to fully power down.
- Switch the system back on using the control panel button and check whether the code clears.
- Inspect the visible motor cable and connector for damage, corrosion, or loose seating, and reseat the connector if accessible.
- Check the motor housing for obvious water or mud contamination and let the bike dry if wet.
- If the code returns immediately after reset, do not continue riding and contact your e-bike dealer for diagnostic and motor testing.
Warranty: A genuine internal motor or sensor fault within the two-year statutory warranty period is normally covered by the manufacturer, while water ingress, crash damage, and worn cables from external causes are typically excluded.
Typical cost: Dealer diagnostics typically run EUR 40 to EUR 80, a Hall sensor or motor service repair around EUR 120 to EUR 250, and a complete motor replacement usually EUR 500 to EUR 900 depending on the Brose model.
Frequently asked
Can I reset brose error 42?
Yes, switch the system fully off using the control panel button, wait around 30 seconds, then switch it back on. If the code reappears the moment the motor is asked to deliver torque, the fault is still present and the bike should not be ridden.
Is it safe to keep riding with brose error 42?
No, motor assist is already disabled and riding on a heavy e-bike without power plus an unresolved internal motor fault risks further damage to the motor or wiring. The bike should be ridden only on unpowered rolling to a workshop or, ideally, transported.
How much does fixing brose error 42 cost and is it under warranty?
A dealer diagnostic is around EUR 40 to EUR 80, sensor-level repairs EUR 120 to EUR 250, and full motor replacement EUR 500 to EUR 900. If the fault is an internal component failure within two years of purchase it is normally covered under the Brose warranty, but water ingress and crash damage are not.
Related Brose codes
Manuals and video
Official source: Brose error code table, Pedego dealer service guide
Not an official Brose document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.