Car Security Alarm Tire Pressure Monitor System OBDTPMS For Toyota For corolla Gas 2014- For corolla Hybrid 2014- Working principle: When the tires are underinflated , the tire radius become smaller , wheel speed become higher , when the tires are overinflated , tire radius become larger at the same time wheel speed become lower . The Car OBD get the original ABS data , once tire underinflated , it result to abnormal data , then monitor alarm . Feature: 1. the screen show the value is not the actual tire pressure value bar, it an is analog value of the tire pressure. 2.the monitor screen show "2.4''mean tire pressure normal . 3.when the tire pressure leak up 20%-25%.it will show "1.8" and alarm. 4.when the tire pressure leak up 50% or more.it will show "1.0" and alarm. OBD TPMS advantages: 1. No need to disassembly device, easy to install. 2. No need to install sensors and replace battery. 3. Safety, it utilize original car ABS data to judge the tire status . can discover tire hidden danger in time. OBD TPMS disadvantages: display the value is not the actual tire pressure value . Learning /Testing steps(Send with Manual): 1.after install.check and ensure the four wheel tire pressure normal . 2.keep pressing the "L"button for 5s till hear the music sound then release your hand.then the screen show asP1. 3.On the flat road ,drive for 1km and control speed lower 70km/h,then the monitor finish learning process.monitor show as P2(display P1 and P2 ,please see the instruction manual). Notice: Don't stop car test, it can't test the tire pressure if stop the car to test.