ZCHondaCRX91

In the near future I'm planning to do a H2B in a CRV. I have everything checked off in my head, but for the ECU I wanted to keep it emissions legal. I live in washington state, so for the emissions test all they really do is plug into the OBD2 diagnostic port (probably check for codes?). So I figured if I get a matching OBD2 ECU for a H22, should it give me any problems?

If it's a manual crv then the ecu doesn't control the transmission, and seems like most of the sensors would be the same. Are the CRV ECU plugs completely different or are they the same as any other OBD2 ecu plugs? If anyone has personal experience that would help also. Thanks.

tony_2018

Not possible but its up to you if you want to use an usdem h22 prelude obd2a/b ecu.

ZCHondaCRX91

What part of it is not possible?

tony_2018

The immobilizer part.

ZCHondaCRX91

It's a pretty common issue, but for these there is bypasses where you just replace the immobilizer unit in the ECU. Or I can just try to find the 1996 ECU (97-01 prelude use the immobilizer). If I just replace the assembly in the ecu, then it will still pass emissions, and won't give me any problems. Here is just one bypass:

OBD-2 / Immobilizer Bypass | .: FF CHIPS :.

tony_2018

So what else are you looking for? You seemed to be well informed.

ZCHondaCRX91

My main question is that the CRV ECU OBD2 plugs are the same as another OBD2 plugs (maybe a few extra pins though)? It seems like it would be the same, but I'm not sure. Then also just wondering if anyone has done it, and any advice they might have. I've only seen a few H2B CRV, and they were mostly converted to OBD1, but it seems they would have to have an OBD2 option for emissions.

tony_2018

judging by the pics I found online of the 97-01 prelude ecu, they look like they use the same obd2 ecu plugs. I think its best if you cross reference the ecu pinouts to the obd2 crv/civic ecu pinouts as there might be extra wiring that need to be ran.

And just to clarify, all 96-01 preluds were OBD2A. Make sure you get the correct parts to work with your specific CRV.

ZCHondaCRX91

Yes, I will just have to stay OBD2A on the CRV end. That leaves either 96-98 as my options for years, unless I swap over the harness.

LinkJ

believe it or not, all 1st gen CRVs are obd2b. You can't use a USDM h22 ecu because i believe the immobilizer and even if you take that to the dealership to get removed correctly, i believe it still looks for traction control which is a separate plug which the CRV does not have. You will throw CEL for that. So if you want to do h22 with crv AWD trans and you wanna pass emissions then you have to get a honda accord obd2b ecu, if they only come obd2a then get the harness which is like 75-100 or something.

i did a straight swap f20b into my crv, gave up AWD for LSD and i was able to plug in the JDM PCB ecu into my crv with stock plugs. yeah, since its JDM obd2 readers don't work, but it plugs up and it works.

ZCHondaCRX91

I remember the JDM H22 ECU's that have traction control are the 4WS models. I don't think all preludes had traction control. I remember the ATTS transmissions using some kind of traction control. I've seen OBD2 H22's swapped in OBD2 Accords without CEL, so either they deleted it successfully or there are ECU's that don't have the traction control plug. Don't the CRV's have traction control though?

I swear I remember seeing some OBD2A CRV's (they were just the 1997 models, I guess there isn't any USDM 1996 CRV) and in 1998 or late 1997 they switched to OBD2B. I might have to rethink this, I wanna keep the AWD so I guess my options are getting thin.