Okay so I am running a b18a1 with a ys1 tranny from a 93 integra in my 89 dx. I have a P75 ecu as well with a conversion harness for the obd0-obd1 conversion and made my own engine harness. At the moment my motor hesitates when you rev it after it is warm. Obviously one of the first things you check when there is a engine problem is the cel codes. My question is how do I check them? This was a conversion so I don't have the blue plug by my ecu to jumper and have the check engine light in the gauge cluster flash. And unlike my original ecu there isn't a light built into the top of the ecu you can watch. Is there any specific pin outs I need to jumper to get it to flash in the gauge cluster? Thanks guys.

 

This is the blue plug I am getting at. However, obd0 from what I know didn't have one. Therefor, I don't.

 

Just ground the CEL pin on the ECU.

 

Do you know what pin it is? I have looked on wiring diagrams and none flat out say "cel".

 

That's because technically it is a "SCS" (Service Check Signal) and if I remember it is D4 on a OBD-1 ECU. You probably didn't look hard enough.

 

probably since i am trying to do research and be at work at the same time. thanks though i will give it a try tonight and post back.

 

What year is the chassis/engine harness? I think 88 and 89 have the service connector in the engine bay rather than by the ECU.

 

He is running a home-made OBD-1 conversion and engine harness, it would probably be easier to just ground the pin-out.

 

It is will be easier to just ground the pin out. The engine harness is far from the original 89 obd0 one. In fact, it is made out of 3 different harnesses. No extra wires and it plugs into the ecu under the dash instead of in the bay.

 

Alright so I went and found the pinout for the SCS and grounded it. With the key on the check engine light was on solid. Unplugged a senor in the bay and cycled the key. Got the error for the senor so it worked. However nothing that the ecu can tell is wrong with my engine so I am back to square one. Thanks though for helping me figure how to check for codes.