Diagnosis
The main brush motor or the sensors that monitor its rotation are overly sensitive or failing. Hair and thread can get wound tightly around the brush ends, near the bearings, where it's hard to see.
How to Fix It
- Remove the main brush. Look closely at the very ends of the brush, where the plastic caps are. Use scissors or a seam ripper to cut away any hair wound around the axle.
- Check the brush chamber itself. Run your finger along the groove where the brush spins to feel for any debris lodged inside.
- Inspect the rubber flap on the brush. If it's torn or deformed, it can create drag and trigger the error. Replace the brush if damaged.
If That Didn't Work
The error can be triggered by a weak battery not providing consistent power to the brush motor. Run a full charge cycle. If the problem persists, the main brush motor assembly may need replacement.
Heads Up
Long-haired pets are the usual culprit. You need to check and clean the brush ends weekly, not just visually inspect the bristles. The L40's suction is powerful enough to pull hair deep into the ends quickly.