I have a curiosity question, I have tried searching the Web and am getting mixed results. Sorry if this has been answered before, I didn't see it anywhere.

What would it take to convert my 95 LX?
I have read that the 95 EX was OBD 2 compliant, I am unsure if that is true. My car has an opening for the DLC, but no connector.
I have seen tons of information on going obd2 to obd, but not much about the other way around.

I assume I would need an ECU, wiring harness, O2 sensor,and obviously the connector but what else?

Or am I completely wrong and it's not possible?

 

Your 95LX is OBD1... For the amount of work it would take to do properly. I don't see any real benefits to going OBD2.

What is your reason for doing this? The ability to read diagnostic codes and real time data with a Scan tool/code reader?

Anything is possible if you are willing to spend the time and money.

ECU
Engine Wiring harness
Dash OBD connector and wiring
You will have to cut and splice some wires as some of the sensors on the OBD1 engine are not in the same places as on the OBD2 engine.

You may be able to by an OBD1 to OBD2 ECU conversion harness, not many people going that route but I'm sure for the right price it can be purchased.

 

Actually kind of, I'm trying to figure out my rough startup that only happens when starting a warm engine. I started thinking about how it would be easier if I had access to the live data.
A friend of mine bought my old 89 Accord (OBD0 I think, no CEL, had to look at the flashing led on the ecu to find codes) and made it obd1. As far as I know our worked great. That's another reason I'm curious on the OBD2 swap.
I know that 95 was a transition year for manufacturers to start getting obd2 compliant, and from what I have read, the California LX's were obd2 compliant.
http://www.obdii.com/connector.html
Are all of the sensors there?

It's not something I'm planning on doing yet, maybe one day.
Sound like a fun project though.

 

1995 Accords with V6 were OBD-II compliant. not the 1995 4 cylinders.

 

The V6 were fully compliant, that I know.
I was just stating what I read on that link I posted
OBDII - On-Board Diagnostic's System - Does My Car Have OBD-II? The Connector and Communications.

That site says that the California LX's were obd2 compliant, which was the main reason my curiosity turned into asking the question. I also saw a hole for the DLC behind my ashtray.

All of that lead me to believe that my car is probably close but not OBD2 compliant.

I have also never seen OBD1 to OBD2 conversion either, but I have seen OBD0 to OBD1 and I have seen OBD2 to OBD1 conversions.

How much different are the OBD1 sensor locations compared to the OBD2 sensor locations.

 

1995 Accord LX and EX V6 were OBD-II.

 

All of them!?

If that's the case then my car is missing a connector.

 

LX V6 and EX V6.

 

Oh that makes sense, you scared me lol.

I actually didn't know that there were V6 LX models, you learn something new everyday.

Is that all it takes, sounds like it would be a pain but fun.

 

Some other things:

94-95: CKP/TDC sensors are inside distributor.
94-95: One O2 sensor.

96-97: CKP/TDC sensors are located down at the crankshaft pulley.
96-97: One primary and one secondary O2 sensor.

As mentioned, different ECM/PCM.

 

Sound like the "right" way means to swap the motor. I don't plan on doing a motor swap unless terrible things occur.

I'm sure a savy guy could do it though haha.

I thought there would have been more hardware involved, I guess the obd1 to 2 is mostly programming.

 

or you could just swap the distributor, oil pump/housing, CKP & TDC sensors and engine harness. No need for a complete engine swap.

The difference between OBD1 & 2 is the use of a different program/data language. Also the amount of specific data that is collected and in turn able to be read from the ECU. The actual engine hardware didn't change all that much between OBD1 and OBD2 on these Accords. Aside from the TDC and CKP sensors being located in a different spot. They still send the exact same information to the ECU whether they are in the distributor or on the crank. You can use the OBD1 TDC & CKP sensors hooked up to an OBD2 ECU and vice versa. Many people run OBD2 vehicles with OBD1 ECU's without swapping engines or all the sensors. Could be done with a reverse conversion harness.

Hope I'm not confusing you even more.

Like I said the only real benefit to switching to OBD2 is being able to read live data and more specific diagnostic codes.

 

Not at all in fact you clarified it more. I was mostly curious about the differences.

Thanks for the info.

 

I'm not so sure they use the v6s and the i4's use the same chassis. It might not fit anyhow.

 

Can't you swap a v6 into the other models?

 

Short answer, Yes!

Although it would just be easier and cheaper to buy a V6 Accord.

The engine bay layout, mount locations and the actual size of the bay are different between the I4 and V6 chassis.

 

That's what I thought although I didn't know that the engine bays were different either.

To be honest I like the I4, plenty peppy and good fuel economy.
I haven't driven a v6 model though

Now that I think about it, it doesn't really sound that hard. Replacing a wire harness is not that hard, it is a PITA though.
Adding an O2 sensor would be easy too, I would most likely have have to pull an exhaust that will support a downstream O2. I could pull the harness for that too.

If we ignore everything else for a moment, would the ecu just plug and play?
Obviously I would get CEL codes if I just plugged in the ECU.

Sounds like a trip to the scrapyard will yield all needed materials.

 

The ECU's do not use the same connector arrangement. It would only be plug and play if you get the complete in-dash and engine wire harness for the OBD2 ECU. Otherwise you need to convert the connectors from OBD1 to OBD2.

 

Ah, that's where the "work" comes in. After looking at the ecu pinout I can see where it would suck.

 

A couple more questions then I'm done here.
While I was looking at the ecu pinouts for the 95 and the 96 4 cylinder cars I noticed a couple of things that didn't match.
1. The 96 has an evap bypass solenoid and the evap control canister pinned to A28 and A29. The 95 doesn't appear to have those to the ecu. Are they mechanically controlled in the 95?
2. The 96 has a fuel tank pressure sensor pinned to D15. Is this present in the 95?
3. What is a VREF?
It is present in my car, but didn't appear to pin in the 96. I have never heard of it either
4. Fuel injection air control, is that an Air Injection Reaction System?
That also doesn't appear to be in the 96.
5. Baro sensor?
I have an vague idea on what it does, it pins to D5 also doesn't appear on the 96.

I'm chasing a warm start issue, I think it's caused by a rich condition and didn't think of checking the EVAP system.

Also my curiosity is getting to me.