00 si wire harness question

[robots]

so i bought a complete swap with the si wire harness still attatched and the si ecu. im putting the swap in a 97 cx hatch. i removed the engine and pulled out the old wire harness, and noticed it had the 3 plugs going into the ecu, and then the green plug off the engine harness into the green plug in the dash harness, but the si engine harness only had two plugs and then the green plug. is this correct?? i have the si harness and ecu? will this still work or do i need to do something else. i was first told it would be completely plug and play but now im not so sure. here are pics of the ecus.


the cx ecu and harness
http://img.photobucket.com/albums/v400/deathbyrobots/cxecu.jpg

and the si ecu and harness
http://img.photobucket.com/albums/v400/deathbyrobots/siecu.jpg

[Silverbeast]

You are going to need to use your harness from your CX and just wire up VTEC. If you dont, then you will need to completley repin the green plug and get a 00 ECU. I would HIGHLY suggest sticking with the harness that came with your car and modifying it.

[civicious]

You can't use an obd2b harness in an obd2a car without replacing the in-car harness with an obd2b. The 96-98 harnesses had all 3 ecu plugs on the engine harness, while the 99-00 harnesses had one plug on the in-car harness and 2 on the engine harness. That, and the green plug is totally different. Just use your CX harness, and add VTEC.

[VashThaStampede]

obd2b- obd2a conversion harness???

[civicious]

All that will do is allow you to use an obd2a ecu with an obd2b harness...which would do absolutely no good in this situation. An obd2b- obd2a harness would let you run an obd2a ecu in an obd2b car, say for instance if you put a 96 GSR ecu into a 99 Si. This isn't an issue that can be fixed with a conversion harness. You either have to install a 99-00 in-car harness or just use your stock harness. Plain and simple.

[robots]

fuck.. well what will i have to do..vtec wise. and what ecu will i have to use?

[fug_mo]

Get a 97 civic ex harness..only need to extend a few wires and already has all of the plugs you need.(vtec)..get an obd2a to obd1 jumper harness and runa chipped obd1 ecu.

[robots]

and will it all match up on the cx engine harness like with the distributor and injectors? and doesnt the cx have 2 o2 sensors and the si have one? and what about a knock sensor? please let me know.

[fug_mo]

Use the ex harness and it will be plug and play,minus having to extend a few wires.
Im not 100% sure about the cx harness.

[robots]

but if i got a new ecu right? shit i bought all this cuz i was told it would plug right in. where can i get an ex harness then?

[fug_mo]

You can use the cx harness,but will require slightly more than ex wiring...none is very hard though.You will need a obd2a-obd2b adaptor harness to run the si ecu.You cant use the si harness without a ton of wiring.I have tried with success,but is difficult.

[robots]

so what kind of wiring is needed? one wire to the vtec siliniod? and what else... will i need to get a new ecu? or will the cx work. or will i have to get the jumper harness and use the si?

[robots]

anyone have a 96-98 ex engine harness???!?!

[XxdsmxX]

so what kind of wiring is needed? one wire to the vtec siliniod? and what else... will i need to get a new ecu? or will the cx work. or will i have to get the jumper harness and use the si?
use your stock cx wire harness it is alot easier..............

[civicious]

use your stock cx wire harness it is alot easier..............


that's the most worthless reply in the history of the internet. He KNOWS it's gonna be easier to rewire his stock harness, he's asking WHAT WIRES IS HE GONNA HAVE TO ADD!!! Gah! What, did you eat a big bowl of dumb for breakfast?


As far as the wiring, you're gonna have to add wires for VTEC solenoid, VTEC oil psi switch, and knock sensor. On top of that, you'll have to move a few wires around for your IACV, since the CX is a 3-wire and the EX/Si/etc is a 2-wire. You can find super detailed instructions on www.ff-squad.com that Katman wrote up, complete with pictures and everything.

If you use an obd2 ecu, using your stock harness is gonna be your best bet, because of the o2 sensors. The CX has both o2 sensor plugs on the harness, because both o2 sensors are on the header. On the EX, there's only one o2 sensor plug on the engine harness, because on EX's the cat isn't integrated onto the header, and the secondary o2 sensor is after the cat on the exhaust pipe. Because of that, EX's have the secondary o2 sensor plug on part of the car-side of the harness.

If you run an obd1 ecu, however, you won't have this problem, as obd1 ecu's only look for one o2 sensor.



here's your best bet, and the cheapest way to do it: rewire your CX harness, get an obd2a-obd1 jumper, and a p30.

[pumpsow]

you can run a gsr ecu, then rewire the harness base on ff-squad info. That what i did with mine, one problem you might encounter is making a pin for the vtec solenoid, vtec oil switch, and knock sensor. If i remember right, you not going to use one of the wire, it should be orange. i took pin from another ecu and use it in the plug so it plug into the ecu :). Or else like the guy above mention. Run p30 but you going to need to make sure all your wiring is correct first or else if you get cel, it hard to trace down. and also need obd2a-obd1 harness.

i did the same swap along time ago.

[UkraineTrain]

Sorry to change the subject, but I wanted to ask the informed people in this thread because I have a 99 EX(5 spd). Is my wiring harness identical to the 99-00 Si harness?

[civicious]

For the most part, yes. A couplea wires on the Si harness are a bit longer than on the EX harness, but other than that they're the same.

[cypher]

that's the most worthless reply in the history of the internet. He KNOWS it's gonna be easier to rewire his stock harness, he's asking WHAT WIRES IS HE GONNA HAVE TO ADD!!! Gah! What, did you eat a big bowl of dumb for breakfast?


As far as the wiring, you're gonna have to add wires for VTEC solenoid, VTEC oil psi switch, and knock sensor. On top of that, you'll have to move a few wires around for your IACV, since the CX is a 3-wire and the EX/Si/etc is a 2-wire. You can find super detailed instructions on www.ff-squad.com (http://www.ff-squad.com/) that Katman wrote up, complete with pictures and everything.

If you use an obd2 ecu, using your stock harness is gonna be your best bet, because of the o2 sensors. The CX has both o2 sensor plugs on the harness, because both o2 sensors are on the header. On the EX, there's only one o2 sensor plug on the engine harness, because on EX's the cat isn't integrated onto the header, and the secondary o2 sensor is after the cat on the exhaust pipe. Because of that, EX's have the secondary o2 sensor plug on part of the car-side of the harness.

If you run an obd1 ecu, however, you won't have this problem, as obd1 ecu's only look for one o2 sensor.



here's your best bet, and the cheapest way to do it: rewire your CX harness, get an obd2a-obd1 jumper, and a p30.


how is that the cheapest way?

rewire the cx for vtec and a obd2a vtec ecu.

no need for the conversion harness and another ecu just to bypass an o2.