Function one: test for 1L15Y-5M48H. Contact the CAS4 computer with this machine.LED1 and LED2 will flashing, this is say the CAS4 computer in good condition. If LED 2 cannot flashing, its mean the CAS4 computer must be with something wrong. Function two: This machine also can test the data of  CAS4 5M48H,but it is could not edit the data. When the light is flashing, it is say in good condition. Otherwise ,it is something wrong.

Function three: after you had made a new one copy key. You also can check and test  this key . put the key upon the machine  with in 10 seconds, if The LED3 light is beginning flashing , it is mean the copy key is successful.