YDS often requires the cable to be assigned to a specific COM port (usually COM1 through COM4). You can change this in the Windows "Device Manager" under "Ports."
To use YDS 1.33 successfully, you need more than just the software:
There are three reliable methods to obtain the software:
Your engine’s battery must be fully charged and the "Key On" for the software to communicate with the ECU. ⚠️ Important Safety Warning