i have a jdm gsr engine in my hatch running the jdm p72. last night i put in the usdm ecu because it is the first thing i did since i am going to try to pass smog. well i went to drive it and it went into limp mode and wouldnt let me shift abouve 5000. is this common when putting a us ecu on a jdm engine. i know that i am missing certain things like the crank angle sensor that is not on jdm engines. would that be what causes it. i need help!

 

Are you sure you're missing Crank Angle sensor? Never heard that.

I do know that some JDM engines lack VTM (vtec oil pressure sensor). Which an USDM ECU will expect to see. That's the big one I can think of off the top of my head.

-PHiZ

 

What engine codes are you throwing?

 

You need to jump the service connector to see what codes are stored. The only issues that I can think of would be on an OBD2/2B JDM B18C. That would be lack of a VTEC pressure switch and the Crank Fluctuation Sensor. That's really the only differences between them.
I imagine the Crank Fluctuation sensor is what you are referring to as the Crank Angle sensor. If you want to add that, you will have to install an OBD2 Integra oil pump then mount the sensor. With the VTEC pressure switch, you can easily wire around it to fool the ECU into thinking it's there which will not throw a CEL. If you get deep into this and need help let me know. I probably made it sound really harder than it seems.

 

So OBD2 jdm engines lack a CKFP sensor? Good info, thanks. Any personal theories as to why?

-PHiZ