[b3lha]

Originally Posted by longassname

Actually the tx from the ecu is pulled high and clipped not clamped and the rx line is clipped on both sides then they go through the 74hc125 to pins 12 and 13 on the 6303

I made a schematic to duplicate the select monitor interface for an interface to a ftdi ttl232r cable: http://www.ecutune.com/posts/ttl232r-selectmonitor.pdf

That's awesome. An interface design that is guaranteed to work!