I've read a bunch of threads already and are constantly getting lost with terminology and other things. So please be gentle....

Car: 99 Honda Accord sedan MT 5spd
New motor: H22a from Japan RHD Auto
ECU: P13

I have the original harness off the F series. The harness that came with the motor and a USDM H22 harness. The ECU has the plugs still in it's ports, but the wires were cut and left enough to connect them to a harness.

None of the harnesses plug into the ECU. And not one of the harnesses plug up directly. So now my car has been on jack stands since March of 2019. What am I missing?

 

Why not get a chipped P28. That works for sure with an H22

 

Your usdm h22 harness is from a manual obd2 prelude?

Emissions is not an issue for you?


If yiu answered yes to these two questions, I recommend you use that harness, the correct obd2 to obd1 conversion harness AND a chipped p28 obd1 ecu like previously mentioned.

 

Emissons are an issue. And couldn't tell you where the USDM H22 harness came from. Looks new.

 

Not looking to tune. And emissions are an issue. Also the P13 is an H22 ECU.

 

I think you're going to have to get an OBD2 to OBD1 harness. I believe the P13 is an OBD1 ECU and your car is OBD2 being a 99. Not sure specifically what H22 you are running either? assuming it's an H22A4

P.S. even if you aren't looking to tune, the P28 is probably still the better option to get out of your ECU.

 

But what year USDM H22 harness do you have?
P13 is an OBDI, your car is OBDII, and your harness is OBD?
If you are trying to stay emissions compliant, you will most likely need a OBDII Prelude P5M(?) PCM to maintain compliance and keep the Accord side of components happy as well.



https://www.hamotorsports.com/pages/tech-library-1

I'd advise looking through any of the applicable articles to your car and engine swap.

Also...



*The above nomenclature of 'OBD' systems is used on Hondas to identify plug layout, it's not an official naming, just a way for hobbyists to categorize the harness connections. There are only two systems OBD and OBDII. OBD gained the '-1' to better differentiate from the '96+ OBD systems, which are indeed called OBDII.*

You have a bit of a clusterfuck of parts going on and need to sort it out to best suite what you are attempting to do

• 99 Accord, which is OBDII with most likely an 'OBDIIa' PCM connection. USDM?
• Unknown year/vehicle origin JDM H22A, with an unknown partial wire harness.
• Unknown year USDM H22 harness.
• P13 ECM that is OBDI

This is a mishmash of parts that are not going to work together easily.
Ideally you would have a PCM and engine harness from a USDM 97-01 Prelude H22 MT base model. Not the SH model.
That would make the wiring side easy(plug & play), as well as emissions compliance much easier, and the added bonus of using more common USDM emissions components for easy replacement/diagnostics when the need comes up. This is assuming a USDM Accord, or similar.

Until we(H-T members) know where the car will be tested it is kinda hard to tell you what you need to get done for the car to work properly with emissions compliance.

If you are in Calif, or similar emissions compliance, the '99 Prelude harness and PCM are the only way to meet compliance. If your region requires OBDII communication your P13 OBDI ECM is not going to have the plug nor capability to communicate.

 

Car has to pass emissions in Illinois.

 

When hubby ordered the engine he specifically told them it needed to be obd2.

 

Engine is stamped H22a.. that's it.

 

Ok.... looking to pick up a new ECU. A P5M. It was supposed to be a plug and play engine swap!!! This is what I get for letting my husband do the work. 😭😭😭😭😭😭😭😭😭😭😭😭😭😭

 

JDM H22 runs on P13

 

But a p13 is OBD1 and it's causing me wiring issues

 

Remember that if you get an OBD2 ECU with immobiliser, it will not start your car.

You will have to adress the immobiliser. Apparently they can be disabled but I have no knowledge of this.

 

That's if there's a chip in your key...

 

You will then need OBDII system retained. A 97-01 Prelude PCM is what you will need as well as a wire harness compatible with that and the H22.
Illinois testing requires checking of the monitors in the PCM via the OBDII port. A JDM OBDII(JOBD) will not properly communicate with the test equipment, nor pass if it did as it is not a Federally or California certified PCM.
Then that should have the correct layout of OBDII sensors/components. But you will need to verify that any sensors/components are the same as the USDM vehicle.
JDM engines are great replacement engines and great for off-road use. But they are not the best way to go for a smog legal swap as the JDM systems are not the same as USDM and may not pass emissions visual inspection. JDM PCM will not pass/work for emissions compliance.
JDM engines don't have a number after the letter. All JDM H22s will be cast 'H22A'.
98-02 Accords and 97-01 Preludes use a transponder and chipped key.
This can be done at a Honda dealership for ~$50.
Prelude transponder can be bypassed in Preludes(https://www.hamotorsports.com/pages/...ss-information),
Accords have the transponder incorporated in to the PCM.
I do not know what wiring differences there are or what would be needed to make the Prelude PCM interface with the Accord dash harness correctly allowing the car to start.

 

I knew my accord key had no chip in the actual key unlike the newer Accords. Hence the price difference in getting an actual key.

 

I'll keep you guys posted. Picking up the Prelude ECU this week.

 

Ok i picked up the new ECU.... but still lost. Do i use the F series engine harness or do I use the H series engine harness?

 

It is always easier to retain the harness that originally came with the car and modify it to work with the new engine. Usually some simple wiring will need to be done like extending some plugs to reach different locations, etc but nothing major.

 

Did you get this thing running yet?

Let us know how it went.