An implemetation to communicate with old GM ECM's specifically 1227165. it runs on a BLACKPILL 10$ board, but any STM 32 would do. The file config.h specifies the pin to be used for ECM communication ...
When this happens, it means that more than one device is trying to use the same I/O port. Open the device manager and see if there are any yellow exclamation points next to any items. You want to ...