The collision sensors consist of two components: a joystick and a circuit board. If your Automower displays the error message "collision sensor active," there are usually three possible issues:

1. The body is not properly attached.
2. The joystick has lost its magnet.
3. The circuit board is defective.

If you experience problems with active collision sensors, always check points 1 and 2 first. If the body is properly attached and the magnets on the joysticks are in place, it is most likely that the circuit board for the collision sensor is defective.