503 - Speed Sensor Error
The bike cannot correctly detect speed.
Medium severity
Caution rideability
Soon urgency
What it means
Assist may be limited because speed feedback is missing.
Common causes
- Magnet too far from sensor
- Wheel magnet missing
- Sensor cable fault
Symptoms
- Speed shows 0
- Assist stops
- Error appears after moving
How to fix it
- Realign magnet
- Check sensor gap
- Secure cable
- Replace speed sensor