W013 is likely the most common error for first time STEPS users. Officially, W013 means Initialization of torque sensor not completed successfully. Don’t fret. It typically occurs when the system is turned on while a load is applied to the crankset. Try turning the system off, ensuring your foot is not on a pedal and the cranks or pedals are not leaning on the ground or against a wall; then turn the system back on again. This should solve the issue.
If you still see the issue try a 'hard reset' - press the power button for 12 seconds and power on once again.
If W013 or any other error code persists, contact your place of purchase or a certified Shimano