CAS tester function: 

1: Is the CAS program running normally?
2: Is the CAS data valid?
3: Does the key have an inductive signal output?
4: Is the key legal and valid?

Tester indicator definition 

1: The indicator light D2 flickers to indicate that the tester CAN bus communicates with the CAS module normally.
2: The indicator light D4 is long on, indicating that the CAS module data is valid.
3: The key is placed in the induction coil, and the D3 indicator flickers, indicating that the key has an LF signal output.
4: The tester beeps, indicating that the key is successfully validated for the valid key of the corresponding CAS module or the newly assigned key.