AVENTON SINCH STEP-THROUGH Error Code 21

Brushless DC Motor Controller

Error 21 indicates a current abnormality detected by the logic board. This failure mode typically originates from a blown MOSFET on the controller circuit board that can no longer regulate the amperage flowing to the motor, triggering an immediate safety shutdown to protect the battery cells.

Motor Quick-Connect Wiring Harness

Mechanical abrasion or thermal stress on the phase wire insulation can cause intermittent shorting between the three main power leads. When these wires contact each other, the resistance drops toward zero, causing a current spike that the system identifies as Error 21.

500W Geared Hub Motor Assembly

Internal degradation of the motor's copper windings or a failure of the internal hall sensors can lead to an improper load profile. If the windings are shorted due to excessive heat, the controller will sense an over-current state and throw the error code to prevent a thermal runaway event.