I tried to convert my 2000 LS ECU to OBD1 to see if any problems might arise. Well I have a problem, there's a check engine light for the ECT temperature circuit. My car runs fine with the original OBD2 ECU, no codes. When the ECT sensor was disconnected there's no initial CEL, it's when I start the car that's when the check light comes on. I'm guessing my ECU shit itself but I know for a fact that it was in working order when it was given to me. Before I did this conversion I made sure the battery was disconnected.





Here's what I'm trying to set up…
My car: 2000 LS.
Conversion harness: brand new Skunk2 harness
ECU: VIRGIN P75 92-95 OBD1 LS/RS

 

My first thought would be a bad conversion harness, but seeing that it is by Skunk2, I highly doubt that.

Try testing the ECU on another OBD1 Honda if you have one handy to see if that is the problem.

But, yes, OBD1 cars have ECT sensors, so there has to be a problem with the harness or ECU if you are getting that problem.

 

Thanks alot for your help.

 

Keep me updated. I had the same problem but I was throwing like 5 or 6 codes because the harness I bought was hacked together by someone who had no idea what they were doing.

It wouldn't hurt to double check the harness, especially that wire that controls the ECT sensor.

 

Yeah I didn't bother to recheck the Skunk2 harness because it was brand new straight out of the box. I'll locate and check the ECT wire like you stated.

I'm actually surprised the car even started with the conversion. I figured I'd have some issues because of the factory anti theft system/immobilizer, whatever they call it.

Thanks again, your always so helpful and have good insight.

 

The older ECU doesn't have an immobilizer in it, so it will always start.

 

Well Däs Schmoo your first thought was correct. I finally found someone with an OBD 1 car and they let me swap ECUs, the ECU that I have in my possession worked fine with no check engine light.

I called Skunk2 to see if I could return the harness but they said I have to return it to the original vendor. When I got a hold of the original vendor they stated that they don't except returns and that I would have to return the harness to the manufacturer.

After both parties declined my request I proceeded to modify the harness. My friend and I rewired the two ECT wires on the harness. To my surprise the harness continues to throw a solid CEL for the ECT sensor. I was hoping to get this resolved so that I could send the ECU to a hondata dealer.

- And here I thought I was doing myself a favor by purchasing what I thought to be a good conversion harness.

 

Sucks about the harness.

If you are looking for a cheap harness that will get the job done, I have one for you. I have purchased two of them, one OBD2b > OBD1 and one OBD2a > OBD1, and they both are running with no problems whatsoever.

http://shopping.lightningmotorsports...ome.php?cat=28

 

How much shipped to Westbrook, CT 06498?

 

Go to that link and order from them. I, myself, am not selling any, but I am just letting you know I have worked with two of those without a single failure. They are well built considering how low the price is.