I usually check mine every couple of weeks with the same tire pressure gauge. Well I started to use a less expensive one I had. Checked the tires on my wife's car which we were taking on a short trip and everything was fine. A half hour down the road the tpms came on and pulled over and checked the tires everyone looked fine. Pulled into gas station and they had a meter where you punch in the number you want and it pumps it to that reading. Started down the road and light went out. Half hour later came on and then went off. Played this game on the way home. Did not have a gauge in the car and I always do. Compared the two gauges I have and the less expensive one was several lbs low compared to the one I usually use. Threw the cheap one away and bought a similar one to my good gauge so I now have a gauge in both cars. Light has not come on. I have always used pencil styled gauges.