JDM Auto Engine installed, USDM ECU throwing codes.
 

Hi everyone,

I just finished installing a JDM engine (1992-3) in my 1993 RX7 Auto. I used the JDM harness and am using the stock USDM ECU. The car runs fine with no problems but is throwing the Check Engine Light for the following codes:

23 - Fuel Thermosensor
28 - EGR Solenoid Valve
38 - AWS Accellerated Warmup Solenoid Valve
39 - Relief 2 Solenoid Valve

If I am not mistaken, there is no AWS or EGR on the JDM engine, but not sure about the others. Not sure if the wiring is pinned differently and they are going to the wrong ecu pins.

Does anyone know for certain what I need to do to eliminate the light from coming on (besides the obvious pulling the bulb)? Does anyone have a JDM wiring diagram for the 1992-3 type engine harness for the automatic car?

I am sure I am not the first to do this, so anyone with previous experience and advice would be great!

Thanks,
Tim McCreary
mccreary1@atlanticbb.net

bump

use a jdm ecu

Excellent choice except I don't have one.

Tim

get one.

FYI most people use the JDM engines as longblocks not drop ins. Thanks!

+1

OBD-I ECUs only throw up codes if there's a short or open in the system. being that your JDM engine doesn't have those some of those sensors (and might be wired wrong) it's throwin up the light.

get a jdm ecu

Most people didn't get a very low mileage JDM with a very good, flexible and soft harness and a car that was missing the USDM intake and wiring harness.

I have received the answer I was looking for through a privage message.

Tim

dude,you dont need a jdm ecu. just fix your fuel thermo sensor because it will put your car into limp mode.maybe not right away . but youll see when your car and ecu reaches a certain parameter.

I would find a usdm wiring harness and install that one. Like others have said the JDM engines are missing a few emissions systems which will throw codes in the US cars.

Or you can run resistors in the systems your engine is missing. I cannt say for sure that will fix all your problems though.

i have a JDM ECU but its for a 5 speed so its probably useless.

I thought you couldn't use the japanese harness on USDM FD's? Guess that is untrue?

Why are you replying to a troubleshooting post from almost a year ago?

It depends on the year.

So if I got a S6 JDM harness for a S6 USDM FD it will work?

The connectors should work. However, I'm not sure how the length of the harness will work out (since they are routed differently).

The S5 harness works, but you have to cut and lengthen the one wire going to the oil pressure sending unit (as I recall).

Thank You! This may be part of the problem. When I replaced the hoses, I noticed the one thermo sensor in the front had dried/cracked wiring. I may be getting a bad reading from it. I will see if I have another one and swap it out.

Tim