944 S3 aka 944 to 968 drivetrain engine conversion
 

So if anyone wants a full pinout of the DME connector and all the gory details including the wire colors here you go:

944 S3 wiring change chart (PDF)

944 S3 wiring change chart (Excel)

I found a very important missing bit of info. It seems DME pin 27 requires Term 15 power aka switched +12V. This is provided via the 14 pin DME connector that is under the dash on the passenger side. It is used primarily to provide the diagnostic port access to the DME. However pin 7 of that connector goes to DME pin 27. The wire at pin 7 is black.

Without power to pin 27 the DME is only half awake and it will appear as though you have a bad DME relay. Then after jumping the relay, testing crank position sensor output all is good. So you check for switched ground at DME pin 36 (pin 85 DME relay) and it fails and the finger points at a bad DME.

I wasted a lot of time chasing that. I should have read all the pin definitions on the DME. Anyway it all works :)

Hopefully it will help you out and you won't go through what I went through. Story at 11 can be found here

Fronkenstein

Thanks for sharing!

Thank you!! I hope i dont run into any weird LHD vs RHD differences!

LHD vs RHD difugaltees
 

I didn't recall seeing LHD / RHD notes on these particular items. If I do I will post them here.

Fronkenstein

Been there done that. Was AWESOME.

Then beere? Tone dhat?

I have a 968 motor in my 944 '86 but somehow during the installation (15 years ago) the diagnostic port seem to have gotten "lost".

How can I add again a diagnostic port?

Thanks.

MN

You will need to find an auto recycler that has a 968 in the yard and ask them for the diag socket and harness under the dash. Its a 19 pin connector on one end and the usual 14 pin socket on the other end. Shouldn't be all that long although I have never seen one up close. It is also possible to convert the cable to use a standard ODB II cable like the one being advertised (EXPENSIVE IMHO here

Apparently the setup is similar in 1988+ 928's, 964 and potentially other models.

Fronkenstein

Thanks.

I have a hard time finding the diagnostic port on PET. Would you know where to look or know the part number?

MN

Do you just want the connector or the entire harness with connectors? If its the latter Porsche probably doesn't have one and if they did it would probably be $10K :)

Fronkenstein

Only connector.

I also have a 928GTS. In comparison to that the 944 is inexpensive.

(Sorry couldn't help myself.)

MN

Mines still going strong after 6 years now? My dad had it swapped when he owned the car but we had to tinker to get the AC to properly activate.

One of the venders printed me a "3" in the S2 font for the rear badge, i should really get that on the car.

I hope you drive that GTS the way it was meant to be driven :)

Yes, I do. It’s the perfect Autobahn Grand Touring Sport car (of its day). Can be driven 150mph all day long (condition allowing), stopping only for oil and fuel.

I love my 78 m22 hybrid. Haven't had it to 150 but at 3200 rpm 110 mph it's a real trip.