I have only just got my Elan and built myself a USB interface cable following the YouTube instruction video. When first connected I was getting nothing but no reply and no data. I tried in vane with 2 laptops with windows 10, 7 and virtual XP. Tried various drivers, the latest and earlier ones specifically for 7 and XP. Set latency to 1 and confirmed ALDL working by putting car into service mode. The only difference to the no reply was a bad echo response with ignition off.
The FTDI TTL USB to serial adapter I used was this one - DSD TECH SH-U09F USB to TTL Adapter Support 3V3 and 5V0 TTL Featuring Genuine FTDI FT232RL IC https://www.amazon.co.uk/dp/B07K76Q2DX/ ... sFbH68N267
The reason I went for this one was it was a genuine FTDI chip, was in a case for protection and came with a fly lead to help connecting wires.
I initially had it set with no jumper between the JP and 3v3 or 5v0 which gave the no reply errors.
After testing and checking all connections, the only thing left to try was the jumper in the different positions. First I tried with jumper between JP and 3v3. The first signs of some success - I was now getting constant no reply errors, but data was showing. This gave me hope, so I moved jumper to 5v0 and JP - SUCCESS
now getting data and no “no reply” errors.