Code 21h: Speed Sensor Fault

Cause

The Code 21h: Speed Sensor Fault Error indicates an issue with the bike's speed sensor and its proper operation. This error occurs when the magnet is out of alignment with the sensor. The magnet should be positioned with its wide-end pointing to the left and in direct alignment with the sensor. While a small margin of error is allowed, anything more than 5 mm (1/4 in) could cause the error to appear.

Solution

Adjust the positioning of the speed sensor magnet on the rim.

Video Instructions

RX Series

City and Rize MD

Text and Photo Instructions

Compare the magnet's placement on your bike and adjust it to be in alignment with the sensor. The picture below of the proper alignment between the magnet and the speed sensor has been provided for your reference. You may temporarily loosen the screw on the magnet to allow for easier adjustment. Please remember to tighten the screw again after making the adjustment to prevent it from becoming misaligned again. If adjusting the magnet's placement does resolve the error code, please move on to the next step.

If Code 21h is still present after aligning the magnet with the speed sensor, please check the connection between the sensor and the motor. The sensor is directly plugged into the motor so you will need to remove the plastic motor cover cap on the left side of the mid-drive motor to access the connector. Disconnect the connector and check for any damaged, bent, or corroded pins and record your findings. Make sure to reconnect the speed sensor firmly once you've inspected the internal ports and pins. If the code is still not resolved at this point, please move on to the next section.

Submit a Warranty Claim or Start a Ticket for Assistance

If Code 21h is still present after performing the troubleshooting steps, please Submit a Warranty Claim or Start a Ticket for Assistance, including all records of the troubleshooting steps you have performed so far, and an agent will reach out to provide further assistance.