OEM MK4 management wiring => Mk1/2/3 harness install FAQ (Now with added dieselness!)

I checked voltage at pins 1 and 3 of the VSS plug and its reading a whopping .03V so I think that that is my issue. I found this thread so I will be doing the same thing to see what happens.

Cheers

 

yup that was it!

 

Dude, you are insane ! You was a right, I just pop in wire into G1/5 to earth and fuel level work fine ! Thank you so much !

 

Hi again. All working great and car up to temp - but my gauge isn’t working. I’ve fitted the Mk3 black coolant sensor. But gauge stays at the bottom when engine is 100% up to temp.

I’ve checked:

1) Brown / white Earth wire is on the head
2) Purple Pin 1 at sensor is connected to yellow red behind the clocks
3) Brown / white pin 3 at sensor is earthed

All tested with multimeter. Only thing I can think is the pins on the sensor are wrong. Anybody have a diagram of the pins on the sensor itself?

 

Thanks mate for that. My issue was I didn’t know the pin layout on the sensor itself - quick google and found it. It now works, but the gauge is over reading a bit. The fan comes on and cools the engine as it should, but the gauge gets up to 110c when the fan comes on.

I believe the gauge is over reading somewhat. I used the black Mk3 sensor (the part number recommended in the first page). Is there another option? (I have an 89 Corrado).

 

Hi rubjonny, AGU DBC and cabrio 92. I make as you wrote, but i have question.
In T6 brown T6/1 you write that best solution is to connect to terminal 87. How to connect when iam usying original trigger (2th position in fusebox)?

and second question is: in T6/5 and T6/6 and T14/6 is connection via E14. is not to much for E14? Lambda shoul be connected via spade N?

Thank you for your answer.

 

Hello! I previously wired a Corrado with 1.8T AEB , an MK3 with AGU and another MK3 with ARL and used this topic and everything went great.
Now I have an Mk2 with CE2 electrics , the engine is an BFB from A4 with the original ecu and the engine harness is from a Mk4 AUM.
I have some problems and I don't know if the wiring is the problem or not. It starts very well , runs perfectly on idle but when I rev it it misfires. Even in the first or second gear it misfires and detonates. The coils are ok , the fuel pump is new . Can someone tell me if i need to change the pinout I have used?
The wiring i used is this :
T6-brown connector
pin 1 -black or black/purple 15 amp fused switched live 15 to ecu T121/3 (g1 pin 4, needs fuse)
pin 2 - purple/white ecu T121/65 to fuel pump relay earth (g1 pin 3)
pin 4 - red/green 20 amp fused constant positive 30 to ecu T121/62 (Y pin 4, needs fuse)
pin 5 - blue/yellow fused 10 amp from fuel pump relay (g1 pin 10, needs fuse)

T14a - 14 pin connector near battery
pin 4 -purple coolant temp sensor (214) Y/M (G2 pin 3, requires resistor to read correctly)
pin 5 - red/purple 10 amp fused switched live to injectors (183) ( G1pin8 )
pin 6 - yellow/black fused 10 amp from fuel pump relay (g1 pin 8, needs fuse)
pin 7 - brown earth (204) (197) (Earth to chassis or battery -VE)
pin 9 - brown/white earth for senders (G1 pin 6)

T10 Orange
pin 1 - grey/white to ecu T121/43 (229) ( diagnostics K diag port)
pin 2 - green/red to ecu T121/81 (Tach signal from ecu via tach adaptor to G1 pin 12)
pin 6 - blue/white ecu T121/54 to speed signal in dash wiring (Hall speed sensor on clocks W pin 1)

 

I have solved the problem. The car had the Mk2 fuel filter and the BFB injectors did't have a fuel pressure regulator and no return line for the fuel.BFB has the fuel pressure regulator incorporated into the fuel filter and the return line also comes from the filter.
So I have fitted an AGU fuel pressure regulator and also used the original Mk2 fuel return line.
Also changed the coils and everything works ok.
Thanks

 

Hi im sergio from spain .
Im swaping an audi a3 1997 1.8t AGU to 1.8t AUM , im using AUM wiring harness and ecu ,i have the 2 aum looms that come from ecu with relay box near brake fluid reservoir, i have installed the dbw pedal with the wire and the blue plug but my a3 wiring only have 2 plugs brown and white , so i dont know what to do with T10 - orange 10 pin plug if its hidden , where can i find it?
If anyone can help me it would be nice !
Sorry if bad english
Thanks

 

You are right its red conector not brown.
I will rewire it
Much apreciated the pinout man
Thanks

 

Tachometer issue RESOLVED: There must be some sort of interference within the CE2 fuse block that amplifies the signal. thanks to a tdiclub forum member who suggested to just connect the wire from the ECU to to cluster. I get an accurate tach now.

Speedometer issue temporarily resolved: I spliced the VSS ignition hot wire to the brake light switch and I have speedometer now as well.

 

Corrado all MOT’d and driving! Huge thanks to this thread

couple of small jobs:

1) The revs are hanging big time on gear changes. So I will have to fit the clutch switch. Is there an easy way to add this on an early Corrado?

2) Will the brake switch be causing any issue? Sounds like it might be. I can see the wiring for that, and the 2 wires to the original Corrado switch, but what about the ignition live and ECU feed - do I need to connect these? If so, what to?

 

Got a suggestion of a micro switch on the clutch pedal, small and probably easy to mount with 2 screws, either have a bracket or part of pedal acting on the lever.
Think the extra wires on brake are only used with cruise control, may be wrong, sure RJ will shed some more light on it.