Special problem pulling engine codes (Experts Only)

[RealMcCoy]

OKay, I'll give it a try after this rain storm finishes. BTW, I assume the negative lead to any ground as pin#12 on my ODBII port may not be a ground.

Yes... I'm sure there is a ground wire in the ODDII plug, but I haven't researched it, so I have no idea which one it would be...

Edit: I must be bored... I just looked it up. Pins 4 & 5 are ground wires in that plug.

[ibsorgn]

I just spent the last hour attempting to pull the codes following your suggestions. Using a voltage meter set on 10v I hooked the (+) lead to pin#1 and the (-) lead to the chassis ground. Turned the ignition key 2 clicks (run) and got a constant voltage but no deflection. This was your recommended procedure, or did I do something wrong? Surely I'm not restricted to using an OBD port ground!

[RealMcCoy]

Are you using an ANALOG volt meter? or a digital volt meter? A DVOM has way too much internal resistence for the ECU to recognize the draw and know it's there...

[ibsorgn]

Are you using an ANALOG volt meter? or a digital volt meter? A DVOM has way too much internal resistence for the ECU to recognize the draw and know it's there...

Analog

[RealMcCoy]

You're confident you've correctly identified pin 1? can you tell if it has a yellow wire?

[ibsorgn]

You're confident you've correctly identified pin 1? can you tell if it has a yellow wire?

Top left for pin #1, used both Pins#4&5 for ground plus tried a chassis ground.

[ibsorgn]

You're confident you've correctly identified pin 1? can you tell if it has a yellow wire?

Are you a TT conversion using the same mix e.g. 1st gen ECU 2nd gen harness?

[RealMcCoy]

Top left for pin #1, used both Pins#4&5 for ground plus tried a chassis ground.

I would confirm the integrity of the yellow wire, as in that it is actually in pin 1, and going to the correct pin of the ECU... But it sounds like you either have a problem with the ECU or your meter has an unusual internal resistence and it isn't working for this task. Have you checked codes with it before? do you have access to any other 1st gen you could you could test it on?

Are you a TT conversion using the same mix e.g. 1st gen ECU 2nd gen harness?

No, why?

[ibsorgn]

I would confirm the integrity of the yellow wire, as in that it is actually in pin 1, and going to the correct pin of the ECU... But it sounds like you either have a problem with the ECU or your meter has an unusual internal resistence and it isn't working for this task. Have you checked codes with it before? do you have access to any other 1st gen you could you could test it on?



No, why?

OKay, I'll start from your first question, no yellow to pin#1
Best I could tell was Pin#1 pink, #2 open, #3 blue, #4 black, #5 black, #6 open #7 yellow, #8 yellow w/red stripe
Pin#9 open, #10 black maybe brown, #11 open, #12 yellow w/dark(maybe brown/black) stripe, #13 yellow w/dark (maybe brown/blue) stripe, #14 white w/red stripe, #15 open, #16 red

Colors to ECU - I don't know

ECU >>>. Not having any problems with it nor have I had any problems so I would guess the ECU is okay.

Multi meter, I have had it for a long time. Used it often. Put my entire race car and the 3000GT together with it, plus diagnosed many items with no apparent problems. I think it's okay.

Check codes with it? Narrow band O2, voltages and continuity on many things. Don't quite understand that question. (Voltage pulses - yes if that is what you mean)

No access to 1st gen vehicles, maybe the only one around that has one.

No, WHY - your response to I question as to whether you were a TT conversation person.
I want to know whether you are responding theoretically or through practical experience? I mean no disrespect as I appreciate your inputs.

[stealthee]

I will tell you that McCoy is the man when it comes to electrical. I'm a do-it-yourselfer and have taught myself a lot of stuff, but I can remember on more than one occasion having an electrical issue and McCoy was the one who had the answer.