1. Remove the back cover of your sensor by sliding the backside down and the front side up.
2. Remove the batteries for around 15 seconds then put them back in
3. Observe if the front light will flash once or repeatedly. If the light will flash repeatedly proceed with pairing. If not, please see step 4.
4. Look for the small black reset button at the right side (while you're facing the dome side of your sensor) then press and hold that button for 10 seconds.
5. The front blue light of your sensor should start flashing every half second. Proceed with pairing.