thread: ECU help (decision) needed

  1. #1
    Tommytank's Avatar
    Jan 2006
    Glasgow, Scotland
    951

    ECU help (decision) needed

    Guys,

    Doing my loom splice now. Got the starter side of things done and I've moved to the boot area, and I've just realised I never got to the root of my mismatched loom / ECU query:



    Annoyingly, it's the 22pin plug that i need to splice into, so I'm kind of jiggered until I find a solution. Am I better to:

    A. Find an ECU that takes the smaller plug, then find the gaps in the PDF wiring manual and see how it goes, or:

    B. Source a 22 pin plug and splice that into my new and old loom, and see where that takes me?

    I guess this question will be answered easier by me asking, has anyone got either of the above that can get me moving again?

    T.

  2. #2
    adamh's Avatar
    Mar 2005
    south east
    4,439
    where did you get the engine, and the loom, ecu? were they all from the same car
    Last edited by adamh; 11-09-2014 at 19:24.
    ......in the bluecorner , fighting out of japan....

  3. #3
    Tommytank's Avatar
    Jan 2006
    Glasgow, Scotland
    951
    Oh hell no. It was a full package, but from all manner of cars. Ironically I have 2 looms and neither of them have a 22 pin plug. :(

  4. #4
    adamh's Avatar
    Mar 2005
    south east
    4,439
    have you checked all over the loom, i remember a 4th ecu plug on my loom it was kind of near the ecu but not quite, i had to chop it off its location and thats what i spliced into, may sound silly but double check for that 4th ecu plug hanging off somewhere else
    ......in the bluecorner , fighting out of japan....

  5. #5
    Tommytank's Avatar
    Jan 2006
    Glasgow, Scotland
    951
    Hmm, I can't see it anywhere post firewall rubber boot. Would it be elsewhere? Also, what is that other plug for then?

  6. #6
    cdwood2010's Avatar
    Sep 2010
    Earls Barton
    6,003
    Shocking deja voodoo here but a mr2 mk2 has one plug left on.the car, which we splice into for the v6 swaps.

    That third plug in.the picture isn't an ecu plug, it's the fan.relay plug.

    So you probably never had it. In which.case the ecu and the loom probably do match.

    And ive got a 22pin plug here that matches the profile, but the colours and pins won't match so some clever wiring will.be required.

    C.

  7. #7
    Tommytank's Avatar
    Jan 2006
    Glasgow, Scotland
    951
    Ugh. Tits.

    Ok guys, the sleeves will be rolled up. What's the solution then? The ECU will need to have the 22 pin regardless, won't it?

    If this is a likely solution in future, an we club together mentally on the pin out solution and I'll document it all for an amendment onto PW's wiring guide? I'm being methodical on this so picturing it along the way will be easy.

  8. #8
    Tommytank's Avatar
    Jan 2006
    Glasgow, Scotland
    951


    Had another look. These are the only 2 multi plugs not in use...

  9. #9
    adamh's Avatar
    Mar 2005
    south east
    4,439
    aye, how many pins do they have, do they fit the ecu?. im editing to say, i think the fourth ecu plug is grey,... you'll need source one, its not the white ones.
    Last edited by adamh; 11-09-2014 at 22:35.
    ......in the bluecorner , fighting out of japan....

  10. #10
    thomp1983's Avatar
    Apr 2012
    Newark, Notts
    906
    on a mk2 the plug you need is for the body harness some of it goes to the fuse box in the engine bay some to the frunk fuse boards and some into the cabin. you need to know what revision the engine loom came from. you'll then need to get a copy of the big gay book identify the name of that connector find it in all the wiring diagrams and confirm what each wire is, then you need to find out what of those wires exist in the mk1 looms match them up then work out whats needed from what's left having done similar with a butchered v6 loom I can tell you this is not going to be fun. you'll also need a full pin out diagram for the turbo ecu you've got

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