OEM management wiring: 1.8T => Mk2 harness install FAQ

Discussion in '1.8 & 1.8T' started by 20v_jimmy, Dec 29, 2009.

  1. rubjonny

    rubjonny Administrator Staff Member Admin

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    you would have to make a new loom from scratch I'm afraid, the ECU plugs are different :(

    if you had a loom made how I describe in my guide here with a T14a plug on it:
    https://www.clubgti.com/forums/inde...-install-faq-now-with-added-dieselness.267196

    then you would leave the T14a alone just redo the splicing for the big ecu plug half to your main loom and re-do any mods on the small ecu plug half you want to make for the oil/coolant sensors if any as per the tips down the bottom of the thread. if it was an early AGU with a T10a then you'll have to splice a 14 pin on your loom, or a 10 pin on the sensor half

    either way check the coilpack harness very carefully, 9 times out of 10 these days it'll be cracked to hell so will need a coilpack repair loom installing on top of it, ideal time to make your mods to coolant/oil sensors
     
  2. Seangtispeed New Member

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    Hello, I have just used the guide on this thread for my AGU into a mk 2 Scirocco build,
    The only thing I am stuck on is I can’t find the wires that go to the Lamda sensor or a plug that looks like it reaches to where it will be?
    My questions are what loom does this come from (large ecu plug or small ecu plug) and how many wires should it have (I don’t have sensor yet) also what colour the wires should be? Any help much appreciated
     
  3. rubjonny

    rubjonny Administrator Staff Member Admin

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    It's a 4 pin plug on the big ecu plug loom, comes out with the 2 pin for the carbon canister. agu just has a narrowband lambda
     
  4. rubjonny

    rubjonny Administrator Staff Member Admin

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    Black and brown twisted pair for signal to exu, black/brown Heater earth to ECU and blue/red heater power tapped into the power feed to t6/5
     
  5. Seangtispeed New Member

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    Thank you very much for quick reply, and thanks for your wiring guide
     
  6. Seangtispeed New Member

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    Hello, what would cause my spark plugs to spark when ignition is turned on but no spark when cranking? Agu into a ce1 scirocco..
     
  7. rubjonny

    rubjonny Administrator Staff Member Admin

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    could be a few things, crank sensor would be on the list. is the throttle body motor and fuel pump working? can you connect to diagnostics?
     
  8. Seangtispeed New Member

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    I have power at fuel pump, but I have not wired it in yet as I’m waiting for lift pump to arrive, I wanted to check for a spark to see if my wiring is working, I didn’t know the throttle body had a motor so I will check that and the crank sensor thanks.
     
  9. Seangtispeed New Member

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    Update: I have checked the plug that goes to the crank sensor and it has live at all three pins, is this right??
     
  10. rubjonny

    rubjonny Administrator Staff Member Admin

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    heres how to check a VR sensor:


    pins 2 and 3 are for the sensor so check across those, pin 1 is the sensor shield
     
  11. Seangtispeed New Member

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    Thanks I will check this tomorrow
     
  12. Seangtispeed New Member

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    Update, I have checked crank sensor and it is working, I have power to throttle body.
    What I don’t have yet is T10/6 wired in as I don’t have gti clocks, could this be a problem?
     
  13. rubjonny

    rubjonny Administrator Staff Member Admin

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    that wouldn't affect starting so you;re ok there. where did you tap your ignition feeds to for the ecu and coilpacks?
     
  14. Seangtispeed New Member

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    Hello, I used your wiring guide, the one with added dieselness, and I got my ecu permanent live from spade P,
    coilpack live via a 15a fuse to fuse slot 17 [top pin] this was the only way I could work out how to connect to relay pin 87.
    I also added a gti fuel pump relay in place of the carb heater relay.
     
  15. rubjonny

    rubjonny Administrator Staff Member Admin

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    for the ignition live you can use G spade 2 or 5 round the back, or D plug pin 2 or 7. your relay should be hooked up like this:

    30 - P spade
    85 - earth claw
    86 - G spade 2 or 5, D/2 or D/7
    87 - to ECU power T6/1 and coilpack T14a/8
     
  16. Seangtispeed New Member

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    Thanks I will try this..
     
  17. Seangtispeed New Member

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    Thanks for this, I have wired as above and I now have live to coils when cranking that I did not before but still no spark, as a process of elimination I have checked and double checked all the wiring to your guide and It is exactly as that.
    The only thing that I can think of is my loom had no ignition amplifier when I got it so I got one from eBay and I have just noticed that the part number is different from what should be on an agu, could this be a cause of the no spark?
     
  18. korea New Member

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    Hi guys,

    I am trying to swap 1.8t APX engin to Corrado G60, now all works except tacho. I use passat b4 dashboard https://prnt.sc/sm8re0 6160594004
    I've tried to search APX ecu pinouts for tachometer, but no result. If anyone can help me with that I will be very appreciative
     
  19. rubjonny

    rubjonny Administrator Staff Member Admin

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    ignition amp might be wrong, what part number is it?

    APX ecu pin for rev counter is 37, green/red
     
  20. Seangtispeed New Member

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    Part number is 3090503514D0
    Looks different to the AGU one as well as it does not have a heat sink on it.
     

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