s15 engine harness to s14 dash harness connector

[Keith_Bergen]

Okay, so i am currently working on an s15 sr20det motor swap in my 95 usdm 240sx and most of it is working out, however where the s15 engine harness connects into the s14 dash harness near the ecu the connectors are the same and plug in except the pin-outs are different from one to the other. The s14 dash harness has more wires going into the connector, most of them most likely from the cruise control which the s15 harness does not have and most of the other pin-outs are not the same either causing heater controls and many other interior functions to not work. I looked on an esm for both the s14 and s15 but do not have what each pin is for and wire colors and such specifically for the connector, i can probably figure out each individually going through the entire esm and see what all goes through there so i can change the pin-outs on the s15 to match the s14 but if there is an easier way I would definately like to hear about it. Please let me know,
Thanks!

[rhd180]

bump


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[Keith_Bergen]

Anyone????

[Monooxide]

I would go through the FSMs, I had to for my S14 SR -> S13 Chassis swap. There weren't any swap guides out.

Luckily for you I think there is a DVD out now, I think.

Good luck.

[Keith_Bergen]

Well here's an update. Found ecu pinout diagrams for both cars, fortunately most wires going through the connector came straight from the ecu so i traced each wire from the connector to the ecu and figured most of them out that way and made a connector with the extra s15 dash harness and leftover s14 engine harness to re-route each wire to the correct pin. It worked out since my engine fired up and ran perfectly this evening! Thanks for all the help, if anyone needs any information on an s15 sr20det swap into an s14 chassis i will happily help you out at least as much as you have done for me! So for all you skeptics out there on the s15 engine swaps, they are much easier then most people make them seem, you just need to make sure you have all the pieces, definitely recommend getting a complete front clip with rear diff and driveshafts. Also need to have a pretty good idea on wiring and problem solving!

[Hawaiian240]

Nice! You should write it up with details and pics. And ask a Mod to get it posted in the Archive and FAQ section.

I'm sure alot of guys would like this info! Glad to hear your S14's running with the S15 SR20DET! It would be interesting to see what kind of numbers your getting from it.

[ForcedNduction]

I have done the same exact thing that you have Keith and traced all signals going to both Engine Control Harnesses. Everything has gone smoothly except for one damn pin used for the consult port. On the S15 side the ECM labels the pin as being "CHECK" signal (pin 23 G/R) while the S14 side has something called "SCICL"(pin 68 G/W) which is a data line used by the ECU to clock serial data to and from a CONSULT device. I dont want to assume that these are the same signal but from the sounds of it they may be the same signals. I just wanted to get a second opinion since you have your swap running. I also plan on posting a wiring harness guide for S15 sr20det harness to S14 chassis(something that doesnt seem to exsist yet...yet).

[Keith_Bergen]

well, honestly i didn't connect that wire to anything. lol. from all the ecu pinout diagrams i could find there were four pinouts that only said each was for the datalink connector and i didn't feel like matching them up so i just taped them off and left them unconnected. I am pretty sure that those four wires go straight to the scan tool connector which i believe is an obd11 so leaving them unconnected will only cause you not to be able to scan it in case your check engine light comes on and from what i heard from my buddy with an sr20 180sx, no one around here has a scan tool for such engines so i couldn't scan it anyways...i'm thinking somewhere down the road i'll probably get a programmable ecu that i can connect directly to a laptop but it does run without connecting that wire. My biggest issue was the eccs relay was a double throw in the s15 harness and only a single in the s14 so it wasn't switching so i wasn't getting any spark. unfortunately i do not know if those wires your talking about are one and the same signal. i would have to trace each harness back to the data link connector to find out for sure.

[Keith_Bergen]

I decided that i may as well connect those wires the other day and found some more information on it...yes, the those two wires you were talking about are one and the same from the harnesse. it is the "check" wire for the data link connector

[Jus Skott]

its late and i know this is stupid. Do they make a conversion harness from OBD1 to OBD2?
~skott

[ForcedNduction]

I know of obd2 to obd1 harnesses. I dont know why you'd want to have obd1 to obd2? Are you talking about running an early sr20 motor with a late sr ecu for emissions?