I have a 1998 Evo V with the OEM ECU. I can connect to the OBD port with a 2.0 cable and read/flash with no issues. However when I hook up and US scan tool to the OBD port it says it can't connect. Any ideas? I have checked all of the wiring and it all matches to the diagrams. Power, grounds, and 2 inputs. I really need to be able to connect to it.

 

There are different OBDII protocols, North America, Europe and Asia. You need a scan tool that works for the JDM. The Autel MD801 or MD802 cover all protocols. Alternatively, change to the Evo 8 ECU.
Check this thread:
https://www.evolutionm.net/forums/ev...?highlight=pin

 

I appreciate the response. I ended up swapping to an VIII ECU and all is well!