Hey guys--

Long story short:
-Someone totaled my 97 civic coupe. Stock. Non vtec (dx). 5 speed.
-I bought a 99 civic coupe shell. Stock. Vtec (ex). 5 speed.
-I swapped everything into the newer shell and now have hit a snag in ecu/wiring.

Obviously, I have a obd2a engine + engine harness + ecu that needs to go INTO a obd2b chassis.

**I've already installed and bolted down everything, which means unplugging the entire engine harness and swapping out alternators, dizzy, etc. is NOT an option.

Now, I know obd2a uses A-C-D ecu plug setup, which is three plugs directly from the engine harness.
However, obd2b uses A-B-C ecu plug setup which is two plugs from engine harness + one plug from chassis for a total of three plugs.

SO, what do I do to get this obd2a ecu + engine + engine harness to work in this obd2b chassis???????
I looked at rywire, boomslang, etc but they do not have a plug and play option for this situation (at least not that I've seen on their site).


Hopefully this was clear and not confusing.

Thanks!!!

 

You can't use that engine harness unless you plan on unpinning the entire ECU connectors and repinning them to OBD2B connectors. To make it easier just get a 99-00 DX/LX engine harness. If you want to reuse your ECU you'll have to get an OBD2B-2A ECU adapter. You'll also need an OBD2B-A distributor adapter if you plan on reusing your Y7's distributor. Alternatively you could swap over the dash harness from your old car but seeing as ones an EX and a coupe and the other is a hatch some accessories potentially won't be available.

 

You need an obd2b harness, obd2b to obd2a conversion harness, and distributor adapter.

Edit: Or be creative and try to get an obd2a to obd2b conversion harness and find an obd2b ecu.

 

Unfortunately I do not have the time to procure and install a new engine harness. BUT I am not averse to unpinning and repinning ecu connectors. And I can easily get the 2b-2a ecu adapter.
If I repinned, would I still need to use the distributor adapter?
What about the engine harness pins on the driver's side? Does that need repinning of any sort?

To repin, I would use these as a guide:
.:OBD2a ECU Pin out Schematics :.
.:OBD2b ECU Pin out Schematics :.
What tricky things in general should I look out for? What about green plugs?



Right now, my current understanding is: re-pin 2a engine harness plugs to 2b plugs. Get 2b>2a ecu adapter. Plug and play and drive. Is this correct?

Thanks!!!!

 

All the repinning will need to be done at the ECU. If you are able to repin to OBD2A you shouldn't need an adapter for the ECU. You can also repin your distributor as well to accommodate the OBD2A plug. As far as the green plug I'd download a manual and start looking at the diagrams