When you see the the spokes Ruut, as your picture shows, the manual says one or more of the conditions aren’t met.
1) It must be on level ground.
2) It must be up to temperature.
3) It must be in Park or Neutral.
When working properly a glass timer will appear.
When I first tried mine after buying it I had the same problem, I found that the engine wasn’t at the right temperature to trigger the sensor.
