Steering Angle Sensor: Description and Operation

An optical steering sensor (photo-cell), mounted on the steering column, is used to establish the rate of the steering wheel rotation.
^ When the steering wheel rotation rate reaches 15 rpm, the output current to the power steering control valve actuator begins to reduce, providing additional power steering assist.
^ Once the steering wheel rotation rate reaches 100 rpm, the output current to the power steering control valve actuator reaches zero and full power steering assist is provided.
^ After the steering wheel rotation rate drops below 15 rpm, the output current returns to the amount of current regulated by the vehicle speed sensor input within one second.