First off i hope this is the right place to post this. If not, i appologize. Ok so here's the deal. Just picked up my s2k and it is in pieces. We did the RHD conversion and started putting it back together. The jdm ignition and all of the wiring is run currently. I can't use the USDM ECU because of the immobilizer, it wouldnt work with the JDM key (please correct me if i am wrong). We started installing the USDM engine harness last night (I have the USDM motor). I have the JDM engine harness as well, but i have read that the jdm harness does not have pins for a vtec or air pump system. Will i be able to plug the USDM engine harness into the JDM ECU, or will it not work? Also, idk if the jdm ECU would throw engine codes because the us engine harness has additional pins on it. I'm not sure whats going to happen when i plug it all in so HOPEFULLY someone on here has some insight. Otherwise it looks like im throwing the motor in this weekend (thats the goal anyway) and winging it I'm sure i could get everything to work without an issue if i bought the AEM EMS, but im not trying to spend over another grand after i just bought the car and tons of parts. I came from on 08 Si so i wa able to buy a 700 flashpro, but since this car is an AP1 i guess i can't do that. Is there a better option over the AEM? im aware there is the kpro, but im not sure what is better.
Thanks in advance for any help!

 

So some searching. The JDM ECU controls the fuel pump relay on a different pin. ( A16 ) vs other market ECU's that use pin A15.

This can be fixed several ways, you can move the pin in the socket but they are a bugger to get out. I open the JDM ECU and solder a bridge on the circuit board where the pins to A15 and A16 meet the main board. This way you haven't modified the car and can still plug in AEM and original USDM ECU's.

 

Thank you for your reply. Thats the big difference i found as well. I have the JDM chasis harness run to the rear so i actually shouldn't have to do that (hopefully anyway). If thats the only difference then i should be fine using the american engine harness. The big difference now is that the JDM cars don't have evap plugs.

 

The fuel pump difference is not in the rear loom. Its in the pin outs at the ECU A plug. The A16/A15 pin switches the fuel pump relay in the square under dash fusebox.

If you can get a loose ECU pin/wire, just plug it into A16 and splice into the wire from A15 and your loom will do both types of ECU. Otherwise just do the solder bridge.