This is a universal JTAG/SWD/UART/SPI/... adapter based around the FT2232H chip. This initially started based off the KT-Link specifications, but has since evolved into the following set of features: ...
In some cases without "main relay output +12v" both pins #1 and #5 should be connected to the single source of +12v. Pin #1 feeds ETB H-bridge, battery voltage sense, gp5 & gp6 high-side +12v, TLE8888 ...