AGG 2 litre - wiring?

Discussion in '8-valve' started by Garyd, Apr 19, 2010.

  1. Garyd Forum Member

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    Has anyone worked out all the engine related connections within the wiring loom for an 'R' reg GTi with the 2 litre AGG engine? This runs the Simos injection/ignition system.

    I have the Haynes current flow diagrams but need more to make it clear what goes where and which bits of the loom I don't need to run the engine.

    thanks for any help anyone can offer.

    Garyd
     
  2. rubjonny

    rubjonny Administrator Staff Member Admin

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    start with the ecu and remove everything that isnt conected to it, simples ;)

    at the fusebox end you should end up with a diagnostics wire, 2 ecu power wires, fuel pump relay trigger, starter cranking wire, lambda power wire and injector power wire.

    I take it this is going into a MK2? what rev counter will you be using?
     
  3. Garyd Forum Member

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    thanks for that info I will see how I get on with that.

    MkII? No, it's going into a T3 Transporter. Is the rev counter a critical part of the Simos system? I am intending to get a 'W' terminal added to the AGG alternator and run the van rev counter.

    Garyd
     
  4. rubjonny

    rubjonny Administrator Staff Member Admin

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    not critical no, just that mk3 rev counter signal doesnt work with mk2 clocks etc. if you're going to run it off the alternator W terminal then that should work just fine :)
     
  5. Garyd Forum Member

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    Are there two air temperature sensors in this (AGG) loom?

    I have a small grey plastic item which looks a bit like a flower with three 'leaves' which go through a hole and three more which spread on the outer surface. I think that this would have fitted into the radiator side of the air filter box. It has brown/white and white/red leads and appears to have connected only to the fuse box area. Did the MkIIIs have an external air temperature display and could this be the sensor for it?

    Within a similar part of the wiring loom I also have a two pin connector with white/yellow and brown/blue leads which come direct from the ECU. The colours and the current flow diagrams suggest that this connector is for the 'intake manifold temperature sensor'. Can anyone tell me what sort of devie this is and where it mounts, please? Presumably it is not on the inlet manifold or it would be wired through the 28a multi-plug? I am guessing that it must also be around the air filter and is important to the ECU?

    Rubjonny, you said :
    at the fusebox end you should end up with
    diagnostics wire,
    2 ECU power wires,
    fuel pump relay trigger,
    starter cranking wire,
    lambda power wire
    injector power wire.


    Are you able to confirm what colours these wires are, please?

    Also, I have identified wires from ECU connector pins which are different colours to those shown on the current flow diagrams. Is this a known issue? For instance T68/20 is brown not brown/white; T68/38 is black/white not black; T68/8 is black/red not black/white.

    thanks
    Garyd
     
  6. rubjonny

    rubjonny Administrator Staff Member Admin

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    1. outside air temp sensor for MFA

    2. inlet air temp sensor, it should be a chunky black round sensor that pushes into a hole on the airbox or rubber inlet boot depending on the model/year. If you have nowhere to put it, what we did on my mates ABF is stuff it into the intake hole on the front of the airbox :)

    3. I have noticed that some wires arnt always the same colours as the VW diagrams, as long as the diagram you are looking at is definitly correct for the ECU you have, then it should be fine to go by ecu pin number alone.

    usually, the colours are:
    diagnostics - grey/white
    ecu relay power - black/yellow
    ecu ignition live feed - black/white
    fuel pump trigger wire - blue/yellow
    starter cranking live - green/red
    lambda power wire - red/white
    injector power - red

    as you have found out though they arnt always that colour, so best to trace the wires back to ecu plug to be 100% if you dont have the fusebox plugs to go on
     
    Last edited: Oct 4, 2017
  7. Garyd Forum Member

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    Thanks Jonny.
    Sorry to keep pestering you but can I seek a little further clarification, please?

    1) I have a grey/white wire but as it comes from pin 43 I assumed it went to the immobiliser.

    2)the black/yellow is the output from the ECU relay, supplying power to the ECU?

    3) black/white supplies 12v when ignition is live to switch the ECU relay on?

    4) blue/yellow (should this be yellow/blue?) - the ecu provides an earth link to switch the fuel pump relay on.

    5) green/red needs to be 12v feed and live when starter is operating. This could be connected to the starter solenoid switching terminal?

    6) red/white supplies 12v direct to lambda probe (ie not via ECU) from same 20A fuse as fuel pump (output from fuel relay).

    7) red supplies 12v direct to injector loom from output of fuel relay (but not via fuse).


    On the immobiliser (which I would like to retain) I have the following wires and questions:

    brown to ring terminal - presumably earth?
    black - presumably power - but ignition or constant live?
    grey/white - has this any connection with 1) above? Do they just join together?
    grey - where does this go?
    Can you help at all on those please?

    Thanks again
    Garyd
     
    Last edited by a moderator: Oct 4, 2017
  8. rubjonny

    rubjonny Administrator Staff Member Admin

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    1) yes, diagnostics/k-line from ecu. it runs to the immob unit, this is how they communicate from each other. the immob unit also passes thru diagnostics info to the vag-com port, another grey/white wire

    2) indeed

    3) its just an additional ecu power feed. as standard it also comes out of the ecu relay, but its not a trigger high power feed if that makes sence, just std ign live feed that is passed thru the relay.

    4) yup fuel pump relay earth trigger. can say it either way I guess :lol:

    5) live when cranking aye, CE2 fusebox this goes to F/5, CE1 it goes to C/18

    6) aye, some models have a seperate lambda probe relay for this, some dont. either way, fusebox end is G1/8 on CE2, E/14 on CE1

    7) on CE2 the injectors get power from the fuel pump relay output, Z/1 (unfused). on some CE1 the injectors get 12v from the ECU relay, pin R/2. others use pin N, which is a fuel pump relay output pin. either is fine. I assume the difference is the early models use a 53 relay for the ecu which can handle the load from ecu and injectors, the later models use a different relay which may not be able to supply both? or they just decided to change it for a laugh, I dunno :lol:

    immob:
    brown - earth
    black - ignition live (terminal 15, coil live so live when ign on and cranking)
    grey/white - to ecu grey/white
    grey - to diagnostics jumper block

    some pics of the jumper block and how it all goes together:
    [​IMG]
    [​IMG]
     
  9. Garyd Forum Member

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    Thanks again, Jonny.

    I don't have the Vagcom port but I am getting the feeling I am going to need it to talk with the ECU. Is that right?

    Do you happen to know what the small unit clipped on the side of the ECU is for? It is about 20mm diameter and 20mm long with a two pin connector attached. Wire colours are green/blue going to a 4 pin connector some near the air filter (I think) and green/black (or maybe grey) going to pin 3 of a 10 pin copnnector which might be near the relay plate.

    Is it important enough for me to need to keep it? Any odeas what the other two connectors should attach to?

    thanks
    Garyd
     
  10. rubjonny

    rubjonny Administrator Staff Member Admin

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    is it a round metal sensor looking thing? if so its the ambient air temp sensor for the a/c
     

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