How to use an OBDII diagnostic port in a 3.6 transplant.

[code7rpd]

You're correct, it is a 14 pin connector.

[code7rpd]

Did you still need the wiring info? I found my notes so I have the info if you still need it. Sorry for the delay.

[Bill Verburg]

Why not post your notes anyway?

[mmasse]

coderpd,

I definetely need those!! Thanks

[code7rpd]

Okay, I made sense out of my notes and here is what I have:

For a 1995 993 Euro OBD I motor you can hook up a 16 pin OBDII connector to othe 14 pin harness coming from the DME. If you get an OBDII connector (I think mine was from an Audi) you will notice that each pin is assigned a number.
Pin 1 will need to be connected to any hot wire that is hot after the ignition key is turned on. You shoul find one in the 14 pin plug from the DME or at the fuel pump relay.

You do not use Pins 2 and 3
Pin 4 and Pin 5 need to be connected to a ground source
Pin 7 goes to the diagnostic K wre in the 14 pin DME plug. The K wire is Orange/White and if you want to insure it is the correct one you can trace it to pin 55 on the DME plug.

Do not use Pin 8
..continued...

[code7rpd]

Pin 9 goes to the engine speed signal which is the blackk/violet on the 14 pin connector

Pin 10 - not used
Pin 11 connects to the knock control signal which is the yellow wire (terminal 50 on the DME)
Pin 12 - not used
Pin 13 - not used
Pin 14 - not used
Pin 15 connects to the L diagnostic wire which is orange/black and originates from terminal 13 on the DME
Pin 16 - constant hot from teh DME relay.

All of the wires you need will come from the 14 pin connector off the DME. If you need to verify (yuo wont have different wires with the same color so this should not be an issue) yuo can take the 55 pin connector on the DME side apart and compare it to a schematic to verify the terminal numbers that the wires originate from. I may have the link with a copy of the 55 pin connector and the designation for each termnal. You can get the metal male and female connectors that fit in the 14 pin plug so the install looks stock and you are not tapping into everything with connectors.

Also if you want to hook up a check engine light (I used the oxy sensor light) you connect the green/grey wire from terminal 21 of the dme harness to one side of the light and supply power (ignition) to the otehr terminal of the light - the DME provides ground for the light when it comes on. I hope this helps. As a side note - since I had a euro OBD I motor my car could only be scanned by a Bosch Hammer. You can also test the check engine light by idling the car and disconnecting some sensors - some will cause the light to come on immediately and others take a while when driving (oxy sensor for example).
There is a way to get fault codes by turning the ignition on and holding the accelerator down and releasing it slowly but I could never get this to work - maybe my throttle cable was not adjusted for wide open throttle.

[code7rpd]

Sorry for the typos - my son is asleep and I am trying to type slowly and quietly.

[mmasse]

THANKS A LOT!!!! I will try it this weekend...If family allows!

[code7rpd]

No problem. Let me know if you need any help.

[MuffinMan]

What OBD2 readers is everyone using for these ports? I am having some niggling issues and want to grab the codes from the computer...but I need to purchase a reader first. Any help/preferences are appreciated.

[beamonk]

I am about to hook up the copnnector. The BMW OBD2 connector has only 3-4 wires. It seems that others have hooked up 5 wires? What kind of connectors did you all use?

[ischmitz]

Hm, as far as I understand only the US version of the 993 Varioram uses OBD-II. The earlier 3.6 cars and all 3.6 Euro models had only OBD-I. A standard scan tool won't do much but I might be wrong. There are some aftermarket conversion kits and a software to read most of the codes. Check Rennlist for details.

For your reference I have attached the pin-out of the 19-pin diagnostics socket and how it is mapped to the Bosch 8-pin Hammer cable. Not all pins are used by the Hammer. I have used a LEMO connector for my conversion since the original 19-pin connector is relatively expensive even as reproduction.



Ingo

[84toy]

Durametric offers a nice software/diagnostic package. There have been some significant improvements lately. I bought a setup for my 95 993 engine. I told Duram the owner it would be nice to be able to switch one ignition system off at a time to check if each system is working properly. A week later I get an e-mail that the software will now do that and go to his site and download the new version. Great customer service. No affiliation.

[ronin]

hey Moses, I have an OBD2-to-Hammer interface cable

[beamonk]

I have a 95 Euro motor, I should have posted that fact. I think we are going to try Durametric software.

[siverson]

I've found this thread very useful so I thought I'd contribute my notes as well. So far, all I've done is glued together notes from various sources.

My project next weekend is to add a standard (non-proprietary) 16-pin OBD-II connector to my 1991 3.6 OBD-I engine so that I can use the durametric tool via standard OBD-I connector. Two reasons for this: (a) the female (in-car) proprietary 19-pin Porsche plug is hard to find and expensive and (the OBD-I connector can be found anywhere for $7) and (b) in theory this may allow me to use a wider range of readers in the future (general OBD-II readers/scanners).

Here are my notes, and I've highlighted discrepancies I found in red.

...removed - update on the next post...

One question: does anyone know if the engine speed sensor and tach lead use the same wire (BK/VI)?

-Steve

[siverson]

Just for reference, here are my updated notes per the 1991 964 wiring schematics:

(The most interesting thing here is to add an OBD-II connector to an early engine to avoid having to use a 19-pin round plug adapter.)

[Kroggers]

I have been looking high and low for a OBD1 connector to install into my 3.6 transplant, and having failed rather bad (OK, I found one via e-bay, but the person was asking £300 for it!!!), I thought I would see if I can use the OBD2 connector.

silverson - did you get this completed and did it work? If I understand correctly, you are still using the Bosch Hammer but with the OBD2 connector.

I am OK with the electrics here and have no problems wiring up the OBD2 connector - it is the reader side I am not sure about. Did you get a OBD2 cable for the Hammer or have you just poked the wires into the connector on the Hammer?

Some more details and pictures would be nice

[siverson]

Yes, this worked fine for me. As has been mentioned, it really doesn't matter what connector you use provided the correct pins are connected. I just chose an OBD-II connector since that's the standard connection on most scanners.

I used the Durametric scanner which is fine, and I'm sure a Hammer would work ok too. Really any OBD-II scanner that supports the "OBD-I ISO 1914 protocol (that the 964 uses)" (last quoted part is my terms/understanding, might not be technically correct).

One photo:



From this thread:

help with: fault Code 34 - Hall signal

-Steve

[Kroggers]

Great news, thank you...

And you are able to both read the codes and reset them with you reader?