Hi there. I would really appreciate a nudge in the right direction with this swap. I've been reading write-ups and trying to find the right information for more than a month now. I am reaching the limit of my google-fu. I could use some real help now.

This is my daily, not some project car. I need this thing on the road. I am a do-it-yourselfer, and I hate relying on other people for things like this, but here I am nonetheless.

The car is a '00 auto civic. The chassis harness has not been changed. The engine is a '97 Y8. The engine harness and ECU are proper for this engine.

I hooked everything up properly, to my knowledge. I am getting no power to the fuel pump or the starter, or anything for that matter, except the cluster (which makes sense, since that's just powered through the fusebox, right?).

I was told I needed a jumper harness for the switch between OBD2A and 2B. I foolishly put no thought into it and bought it without understanding the differences. When I went to plug it up I realized, this is probably for an ENGINE harness that is OBD2B, and an ECU that is OBD2A. This doesn't apply to me, as my engine harness, ecu and engine are all out of the same car, and match. I do have a 4th ecu plug hanging, but my understand is that is just for automatic functionality, and I am swapping to manual. The chassis harness plug is the last thing that doesn't match.

When I look at the "c131" plug, or the green chassis-to-engine harness plugs, and the pin-outs associated with them, they are nowhere near the same. I am assuming the fuel pump and the starter, among other things, get signal through the chassis harness.

So from there I thought all I had to do was re-pin the green connector to where they needed to go. However, the Y8 harness has 7 more PGM-FI pins, the Y7 doesn't have a "Charging" pin.

Does this mean some functions were moved from the chassis harness straight to the ecu later on? Does this also mean I have to find the things that used to go to the chassis plug, and re-pin them to the ecu?

Thanks in advance.

 

I'm going to be honest, I did not fully read your post.

but from what I gathered, your using a OBD2A (96-98) in a OBD2B car (99-00)?

EDIT. Ok I read more.

Are you trying to use a OBD2A harness and ECU in the 2000 civic? If this is the case, it will never work without changing the chassis harness.

 

I don't know how you searched for a month and didn't find this answer... because I know I have posted it about fifty times myself !!! LOL

It is ALWAYS best to use the engine harness that originally came with the car, so if you still have this, use it and modify it as necessary to fit the engine that you intend to install into the vehicle. If you are not comfortable modifying the engine harness, you can use a '99-00 Civic EX manual engine harness. The only change I believe you will have to do with this harness is either change the distributor plug (or buy an adapter plug) OR source a '99-00 Y8 Distributor and bolt it on the '97 Y8 engine. You will then need an OBD-2B -> OBD-2A ECU adapter harness and then the '97 ECU will plug right in. Purchase an Auto-to-Manual conversion harness from ChuckChainz on this forum, install that, and you should be able to drive this car.