Learning engine bay - What is this ?

[Dionk]

Hi all

I was under the hood of my 02 today and I just found this connecter with a cover on it (spray painted red...thanks to PO).  Can anyone help identify what it is and does? Thanks

Dionk 

 

[TobyB]

That's your OBD 0 port.

 

Look at the wiring diagram- it pulls out the starter switch, the points contact, and a few other things.

 

t

 

['76mintgrün'02]

OBD zero...   

 

While you are searching, look up Pat Allen's diagnostic box.

Super cool tool.

Tom

[mvliotta]

I have two of those. One in the same location as the OP, and the other on top of valve cover... although not wired up. Were early cars supposed have two?

 

[zinz]

The one on the valve cover is superfluous... may as well send it to me 

 

Ed

 

Steve or MikeS may chime in about that particular valve cover port location... as I remember, they are a hard-to-find item.

[Conserv]

1 hour ago, zinz said:

The one on the valve cover is superfluous... may as well send it to me 

 

Ed

 

Steve or MikeS may chime in about that particular valve cover port location... as I remember, they are a hard-to-find item.

 

+1

 

I haven't been able to determine when the second diagnostic port arrived or departed.  The reason is largely because so many cars originally equipped with the port -- it tests the primary wiring, as far as I know, but I'm open to additional information -- lost the port the first time an owner changed the spark plug wires.

 

I'd guess the valve-cover-mounted port arrived in approximately 1971 (maybe it was with the Modell '71 in April of that year) and disappeared in 1974-ish.

 

Regards,

 

Steve

 

[Mike Self]

My '73 has that valve cover port--or had, 'till I removed it since I didn't have the factory diagnosis tool to utilize it.  It's in the same box with all the emissions stuff that came off about the same time.  A 72 or later owner's manual should describe what functions the valve cover port is designed to test; I just don't remember since I never used it.

 

mike

[JohnH]

Many of the diagnostic tests that use diagnostic port 1 and 2 can be found in the blue service manuals which reside in the Articles section of this site.