After much trial and error, I figured it out. You need to open the sensor, remove the battery, put the battery back in, wait until the red light comes on, close the sensor, wait until the light goes off, go to Add Sensor, remove, then push the button quickly (don't hold it in), then the Almond+ will show the sensor removed message, and the red light will start blinking on the sensor. Then I selected add, pushed the button quickly again, it added it, set it to Motion Detector, and it found it, and now displays the temperature as well, which is what I was trying to accomplish the whole time. Thanks Lars, once again!