Self-Diagnostic Function
By connecting the HDS to the data link connector (DLC), the HDS can retrieve the diagnostic information from the MICU via a diagnostic line called K-LINE. The K-LINE is separate from the CAN lines, and is connected to the CAN related ECUs. The MICU is a gateway between the HDS and B-CAN related ECUs, and it sends B-CAN diagnostic information to the HDS. When doing a function test with the HDS, the HDS sends an output signal through the K-LINE to the MICU. The MICU either relays the request to another ECU or commands the function itself.