ECU Plug and Wire Mismatch Issue?

[YUPOK]

I have a 95 Talon TSI AWD that I am restoring.

The car was originally Automatic and then converted to 5 speed.

I went to plug in my EPROM ECU into the car only to find I was missing one of the yellow plugs. The 16 prong yellow plug was cut out of the harness. So I called my buddy and sure enough he had a butchered harness out of a 96.

I got the plug from him and started to match up all the wires from the cut harness to the plug. Much to my dismay I have one wire left on the plug. It is Green with a Black trace. The harness has a White wire with Green trace and two silver spots and Orange with Black trace and two silver spots.

All the other wires match up. SO I have two wires coming from harness and one wire with different color going to plug.

Is it possible one of these wires from the harness is for the automatic? How should I wire this for the converted 5 speed?

Thanks for all your help.

 

[DogWhistle]

On your ECU, the 16-prong plug is known as Connector B-54.

Out of 16 ECU pin locations, only 8 wires are connected to the plug (4 on the top row, 4 on the bottom row).

On your harness: The White with Green trace is for the Transaxle (auto trans) and the Orange with a Black trace is also for the Transaxle.

As for the wire coming out of the plug, there are only 3 Green with Black trace wires used on the ECU: 2 of them are with the dark green are for the Idle Speed Air Control Valve and for the Cooling Fan Relay - Low Speed. There is a Light Green with Black trace used for the Manifold Differential Pressure Sensor.

It is important to note that none of these 3 Green with Black Trace wires go to the B-54 connector. Take a count; you should have 8 wires going into the 16-pin connector. If you have 9, a wire pulled out of another connector.

 

[YUPOK]

I am almost in tears right now. Thank you so much for that perfect response.

Yes it is entirely possible I have another wire MIA. I will do a count and re-trace my steps to make sure everything is connected right.

As far as those two wires off the harness for the auto trans axle, is it safe to just leave them out for my 5 speed setup?

Thanks again, I'm one step closer to actually getting this car on the road and out of the weeds.

 

[DogWhistle]

Glad to help. Just paying it forward.

Yes, you can leave those two wires disconnected while you have the 5-speed in place. As a precaution, you should also unplug your TCU (transmission control unit), the slightly smaller gold box next to the ecu. This will ensure that both of those unterminated wires don't ever 'go hot' and short out against the body somewhere.

Glad to see another DSM hit the road!