Data Link pin schematic, '97 OBS

[Ozonkiller]

I've got a '97 OBS with the 7.3 powerstroke, 2wd., Automatic

Multiple shops have tried to hook up to the OBD style connector under the dash and with no success. It's as if the computer doesn't exist.

The truck runs fine except for the occasional blinking O.D. light, which is why I'm trying to hook up and pull a code.

Yes the fuse is good and I have battery voltage to pin #16.

I have searched and searched and I have found numerous pictures and diagrams, but nothing that is like what I have in my truck.

My data link connector uses pins number 2, 4, 5, 10, 13 and 16.

That's only 6 pins. Every diagram and picture I've found uses 7 pins. I have had zero success in finding the exact configuration of the pin count and location that I have in this truck.

There are only 6 wires in the harness going to the plug and everything looks unaltered.

Can anyone out there tell me where these pins/wires go, especially to the PCM so that I can verify that it's not a wiring problem before I condemn the PCM.

Thanks for your time.

Tom

[BigFuel]

Dumb question, the key is in run when you try to connect to the PCM correct? It won't work with the key off. I don't have my wiring diagram on me till late tonight so hopefully someone else will chime in sooner. I went to a shop once to get my wife's truck smogged and they couldn't get the scanner to connect to the PCM and told us the PCM was bad. The idiots didn't know that trucks do not conform to '97 ODB II requirements (they didn't have to conform till like 2000) and all they had to do was turn the key to RUN. I showed them how to use their equipment and drove away not to let them near the truck again.

Another question, does your speedo bounce a little as you drive. Can happen at specific speeds like between 40-50.

[Ozonkiller]

Yep,

Key On, key off. Nada, zero, zip.

Everything from borrowing my neighbor's scanner & Autozone to a couple of very reputable shops. Same results.

My plan is to meter some of the basic stuff, mainly the wiring before I decide to let someone else have a shot at it or stab a new PCM in it. I do have a line on a new, in the box PCM for fairly reasonable money.

[erics diesel]

not all scanners can read an obs diesel pcm

[Ozonkiller]

Yep, I'm aware of that. The trans and the diesel shops that I used were using scanners that looked like they belonged in an intensive care unit. They had all of the "Ford specific" variations of the "not quite OBD2" stuff.

I can understand that my neighbors Snap On scanner or the guys at Autozone couldn't pull it up but not these guys.

[Patrick Feeley]

Straight out of the 97 EVTM for C227, Data Link Connector:

Pin 2: Circuit 914 (T/O), Data (+) from PCM pin 16, through C202 (firewall feedthrough connector)
Pin 4: Circuit 57 (BK), Ground
Pin 5: Circuit 570 (BK/W), Ground through C202
Pin 10: Circuit 915 (PK/LB), Data (-) from PCM pin 15, through C202
Pin 13: Circuit 107 (P), PCM Input from PCM pin 13, through C202
Pin 16: Circuit 40 (LB/W), Hot at All Times from Underdash fuse 16 (15A)
All other pins are NOT USED

Cheers!

[Ozonkiller]

NOW THAT'S WHAT I'M TALKING ABOUT!!!

Thanks soooo much. That is exactly what I'm looking for. I'll just bet (I'm hoping) that it's at the firewall connector. I never thought to look there.

Thanks again for your time.

I'll let you know what I find.

Tom