Very disappointed with these sensors. Since installing it, I've had to go through several iterations of the learning process to get it working. After installation, one of the rear sensors stopped communicating with the car. The next day the other rear sensor also failed. As far as I can tell, the transmitters and/or batteries in these devices are not working as expected. Since these were new sensors I can only conclude that their batteries are fine and their transmitters are not powerful enough to keep in touch. Now I have to spend money to replace the rear sensors. upset.