KOEO Questions/Now I Have a CEL Haha

[Shhhh]

1989 Mustang LX 5.0 5spd.

Using a Haynes repair manual.

Figured I'd pull some codes since I'm having some issues what almost feels like the engine is breaking up or studdering at high rpms. Along with a hard start condition when its warm outside. Ended up not pulling any codes. The CEL just stays on with KOEO and never flashes.

I used http://sbftech.com/index.php/topic,2471.0.html write up and it didnt really get me anywhere.

I looked online and it seemed like a fairly easy thing to do. I go out to the garage and proceed to fudge things up haha. looked for the gray connector and didnt see anything. I instantly disconnect the underhood lamp connector and jump it to the test connecter because "the online how-to probably ment brown connector when they said gray." Went back inside the house and then read the WARNING- Do no jump brown connector to Signal Return part of the write up. Whoops, hahaha. So now I cant find the gray connector.

Checked in my wiring diagram and it shows it should be a T/R wire going to a Gray connector. The only T/R wire I see is inside the Test Connector and not leading to a stand along gray connector.


I see the T/LG, BK/W, T and T/R all inside the Test Connector. Notice there is no Y/BK wire which my wiring diagram shows being the EEC Test Connector #2. The T/R being in what my wiring diagram says should be an empty slot. Jumped the T/R to the BK/W(Signal Return on the Test Connector) and the CEL just stays on and doesn't flash. I used the volt meter method and it just shows like 11.75v constent.


The car still starts and runs great(maybe better then before!) but now the CEL is on hahaha. Guessing that probably has something to do with me jumping 12v's to the Signal Return wire. Where do I even start?

 

[Shhhh]

Went out and bought a code reader and the only male prong on the reader that actually connects to anything is the BK/W wire. Nothing happened when I tried KOEO.

 

[FISHTAIL]

Yeah, you'll need that grey connector to run the self tests. It's there, you just have to find it. I've used that writeup on many mustangs, dozens of times without issue. I've seen cars where the factory plastic holder is in place for all the connectors, and others were that little grey self test pin has been taped up against the main harness, or cutoff completely. Just look closer..it's probably there. Most likely it's shoved down under something between the brake booster and the fender.

 

[Shhhh]

Yeah, you'll need that grey connector to run the self tests. It's there, you just have to find it. I've used that writeup on many mustangs, dozens of times without issue. I've seen cars where the factory plastic holder is in place for all the connectors, and others were that little grey self test pin has been taped up against the main harness, or cutoff completely. Just look closer..it's probably there. Most likely it's shoved down under something between the brake booster and the fender.

Just looked again and pulled the loom out of the way. No gray connector. Does the picture I posted of the EEC Test Connector look correct? The wire placement and colors?

4 Wires going to the EEC Test Connector

 

[FISHTAIL]

Great. Alright, let me check mine when I get home. I'll post a picture of which loom it's coming out of so we can find it. It looks like someone may have trimmed it and covered it up for some reason.

 

[Shhhh]

Great. Alright, let me check mine when I get home. I'll post a picture of which loom it's coming out of so we can find it. It looks like someone may have trimmed it and covered it up for some reason.

Some of the wires were actually in the wrong Self Test Output pin location but after checking out the wiring diagram and getting some help from some people at corral.net I think I got that squared away(For the most part). I still dont see a Y/BK wire anyone like it has on the diagram. It seems like the Self Test Input wire(T/RD per Haynes, some people's diagram have it listed as W/R) was placed inside the STO plug in pin 3(farthest to the left when looking at the face of STO). Maybe the Gray connector broke off at one point and a previous owner didnt want a loose wire hanging around?

I posted a lot more pictures and info on Corral as well. Link to the topic I posted on Corral---http://forums.corral.net/forums/5-0-5-8-engine-tech/1797113-koeo-questions-now-i-have-cel-haha.html


Now I'm just trying to decide if I should order a new computer from Auto Zone or try to fix this one. This one says its for a Federal Emission, Manual Transmission and Sedan. Sounds like the write one for me correct?
http://www.autozone.com/autozone/parts/Cardone-Reman-Engine-Control-Computer/1989-Ford-Mustang/_/N-ihaxeZ9gsp8?itemIdentifier=11297_351148_0_2425%2C3498%2C4299

 

[Shhhh]

Just got back from Autozone, Advance and Napa and no one can order a new computer. Any idea where to pick one up from or order online?

 

[FISHTAIL]

You'll have to get a used one. I see them go up for sale ALL the time on FBA. I'll ask for you. What broke on yours? If it's just a blown cap, that's pretty easy to fix.

 

[FISHTAIL]

ok, took some pics of my 92 vert. Still has the connector in the cover. I'll upload them tomorrow.

 

[Shhhh]

ok, took some pics of my 92 vert. Still has the connector in the cover. I'll upload them tomorrow.

Ok thanks

 

[FISHTAIL]

Crap, glad you posted. Give me a couple.

 

[FISHTAIL]

The test wire comes out of the same harness, same loom. It should be right there..somewhere.