View Full Version : 3sgte 3rd ECU Plug

09-05-2006, 11:40 PM
How do i wire that third plug fo rthe 3s ECU i have a 92 Gt and a 2nd gen 3s st185. Ive searched the forum and have not found anything useful. Please help

Thanks for your time

09-06-2006, 03:23 AM
I'm in the process of this. FInd out the year of your clip. Is it a JDM or USDM? YOu need the pinout's for both your car's ecu and the engine's ecu. YOu then splice the two together.

09-06-2006, 04:28 AM
Im also in the process of this, I have a 90-91 jdm clip, do you have the JDM pinout? Im using the usdm cause i cant find the jdm one. The engine will run with it unpluged though.

09-06-2006, 01:54 PM
Nope i dont have the jdm, I dont have any thing thats why im so lost when i read other posts about this same plug. Its a jdm second gen st185 i cant find the year but the plug has 22 pins.

09-06-2006, 10:32 PM
to tell the year count the exhaust manifold studs. 7 = 90-91 9 = 92-93
Im in the same boat as you man. but I got mine cranked up the other day, without the plug plugged in. runs good, but i want my warning light. You can open up your 5sfe ECU and it says what wire should go where printed on the board. or i can send you a 5sfe 90-91 pinout.

09-06-2006, 10:54 PM
Either that or.. you can get the part number of the ecu and go to 1sttoyotaparts.com YOu should be able to find it. Otherwise.. open it up. If you have two boards it's 92-93, if it's got one board then.. it's 90-91.

I'm not sure exactly what the difference between jdm and usdm is with the 3rd plug. I'll look it up shortly. It'd really help to know the year of the ecu though.

09-07-2006, 01:56 PM
I believe its a 90-91, well i counted the manifold bolts and there's 7 so im assuming its a 90-91. Any thing will help i just want car back. its been like 4 months since i drove my car since the 5sfe crapped out. but it sux every day not driven it.

09-07-2006, 07:22 PM
Let's see.. this would be your existing ecu pinout.

i'm trying to source a 90-91 JDM 3sgte ECU pinout...

DO you have any wiring diagrams?

09-07-2006, 07:55 PM
i believe this onen is for the usdm st185 but i dont know. Here is the link


09-08-2006, 01:43 AM
That looks like a USDM 92-93 ECU. not what you need. It'll be fairly simple, as the wires will match up with each other(colorwise that is.)

09-08-2006, 04:46 AM
Ok so how exactly do i rewire that plug, not just matching wires i dont want to mess anything up. Plus i got bad news its late but i tried to start the car and it just kinda jumps and sputters then dies. I try to keep it alive with the gas but it didnt work but it worked a little but it still dies. What could it be? i would do investigating but its late and i gatta go to work tomorrow. Could it be the timing or you think its plugs cause i didnt change umm plus i thought thaT third plug controlled the fuel pump and if i dont have it plugged then doesnt that mean no fuel. iono any help will really be appreciated.

i wan tmy car back :(

09-08-2006, 05:38 AM
I'm pretty sure for right now you should jump the connectors on the diag. port to leave the FP on constant. It is somewhere on the site.

09-08-2006, 07:54 AM
hey man, i iwired my 3rd plug in today. works great. I think i only connnect 5 wires. 3 of them batt one called els and the other one was the warning light. also redid the c.o.r make sure you do that. I did jump the connector and that seems to be fine. Oh and I used the usdm pinout.

09-08-2006, 02:45 PM
how do you jump out the fuel pump, also how do you re-wire that circuit opening relay.
WEll hopefully that plug is whats maken it run funky.

09-08-2006, 06:59 PM
connect teh b+ and the Fp on the diagnostics box with a piece of wire. as for the relay. The wires are actually in the same place I just wired in the relay for the st185 and all is good. Color matching the wires is a good start. all the ones i connected were exactly the same color and silver band. I can get you a pic later tonight after i get off work.

09-08-2006, 07:27 PM
Yeah... took me about an hour to rewire 10 wires or so on the 3rd plug, as the guy that owned it before decided to splice the wires with crimps. It's really easy if you have the correct diagrams, so find them, or just splice the wires together by color. The car WILL run without that third plug, you just won't get any "idiot lights" such as temp, check engine light, etc.

09-08-2006, 09:26 PM
Yea imma try to wire it right now. I have a problem, i jumped the pump and the car starts, but I have to give it gas for it to stay running. It wont idle at all, what do yall guys think.

09-09-2006, 03:29 AM
vacuum or afm plug.
mine started and ran fine.

09-09-2006, 06:03 AM
Well i plugd all the vacuum and it seems to be idleing fine but its a little low on rpm's. Next i realy need a picture cuz i matched all the wires that i could from each plug and i almost fried my ecu. I NEED PICS. So i clipped all the wires and now im back to square one, but theres no more frying so thats good. Also I tried to drive it and it has super lag, any idea's.

09-09-2006, 04:12 PM
Also when you say rewire that C.O.R are yall talkin about the little balck 12v box, cause if so imma little confused about that cause ther's a wire and a box which one?

09-09-2006, 04:32 PM
I dont see how you could almost fry your ecu unless you're matching up the wrong colors. Just make sure you know which pink wire is which. One is the CEL light and one is the battery I believe. I'd show you mine, but it would be useless as I have a 92-93 plug and the 92-93 plug has 24 pins I believe and the 90-91 one has 10 pins.

09-09-2006, 09:50 PM
What about the Circuit opening relay do i have to re-wire that or what? And do you mean the wire or the box

09-09-2006, 11:37 PM
Things you most likely have and need to be rewired...
AC A/C magnetic switch BLACK/W
ACT AC amplifier LG/BLACK
SPD Speed sensor BLUE/W (I didn't have this.. don't think 92-93 3sgte's have them)
ATS AC Amp Blue/Y
FPR Fuel Pump Relay GRAY (I didn't use this as I bridged it)
W Malfunction Indicator Lamp PINK
STP Stop Light Switch G/W
FC Circuit Opening Relay GREEN
ELS Headlight Defogger ORANGE
+B1 SFI Main relay BLACK/Y
+B SFI Main Relay BlACK/Y

You may have others, you migth not have some of these... I don't know. You should probably take some pictures.

09-10-2006, 01:47 AM
thanks alot man imma take pics so yall can see. But all those wires look and sound pretty

09-11-2006, 04:47 AM
Can you guys please explain better on how you "rewire the Circuit Opening Relay", and why can't the Fuel Pump be wired in correctly?

09-12-2006, 05:51 AM
The circuit opening relay isn't hard at all..... I guess it depends on the ecu. I just had to wire it in normally because it was in the interior connector and I just spliced it into the 3rd plug.

Fuel pump is on the body harness on an alltrac.. I believe. YOu can rewire it, you just have to send a wire from the resistor to the ecu. It's easier just to bridge the connection in the diagnostics box.

09-12-2006, 11:29 PM
Well then if the COR is not in your wiring for the third plug what do you do.

09-13-2006, 04:03 AM
the COR is in the body wirring all you need to do is attach the alltrac relay plug and plug it up. All the wires match up, color wise.

09-13-2006, 11:14 PM
ok, so the plug that plugs into the little black box (COR) has to come from the clip so the the black box can plug in. I have a 91 jdm gt-four clip, does it matter?

09-14-2006, 04:07 AM
thats what i have, and yes you need to cut it out of the clip and attach it to your car in the same location as the other one and use the relay that came with the clip.