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Thread: Two Sensors Disabled. CPS and Manifold Pressure.

  1. #1
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    Two Sensors Disabled. CPS and Manifold Pressure.

    Goodday Gentlemen,
    Took my 08XB12Ss in for a service the other day together with a hard copy of the ECMDroid output of the ECM configuration of the bike. The mechanic told me two sensors that the bike had were disabled, Crankshaft Position and Manifold Pressure. When I enabled the CPS I got a trouble code: Causes 0 | Map short to supply voltage / Broken wire. And when the Manifold Pressure sensor was enabled the engine light came on - disable it engine light off.
    So I'm running the bike with those sensors disabled as they have been since I bought it new (in 2009).
    Very little support here on the island (Mallorca) and the Harley people I bought it from hated Buells and were happy to see it go.
    The bike ran very roughly with the stock ECM and hot to the point of the front header pipe melting through! I put a race ECM in and that made a big difference.
    I'd appreciate any thoughts, suggestions from the forum.

    Cheers and thanks,
    Seb.

  2. #2
    Senior Member Cooter's Avatar
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    Welcome to the forum! I can't imagine theres many Buells on that Island

    Thats not what that means in ECMDroid. IMO, if it runs well, leave it alone.

    It means that the ECM is set to simply ignore trouble codes from those sensors. A by-product of whatever tune happens to be in your "race ECM" box. Where did you get the ECM? Since the box is identical in everyway to the OE box (with the exception of the branding), do you know what tune is actually in it?

    These do run very rough. #Harleygallup #V-twinlyfe. The headpipe will get normally get hot enough, from a dull red glow in a dark garage to a bright orange or even yellow with no airflow and bad habits (see YouTube for drunken idiots doing burnouts), but melting? Uh, No. Your bikes safeties will shut it down well before 300* engine temp. and Stainless steel melts at about 1500*C, which is almost 2800*F. Sure thats combusition temp vs engine temp but no, not even close. A brittle stainless steel head pipe cracking can happen easily if the header is mounted wrong, loose, broken mount, broken stud, etc. So check your mounts and assembly procedure in this: http://buellmods.com

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    Thanks for the info Cooter. So the sensors are active but errors ignored. Curious. The map short/broken wire error on the CPS worried me. It makes sense for the Bank Angle Sensor which failed and I eventually tracked down and disabled through researching this forum. The random cutouts were very disturbing.
    As for the melt through, it was at the first bend of the front header pipe. I had taped up that section to reduce hot air flow through the right hand scoop to the rear cyclinder and to stop my right leg cooking. So that may have contributed to it. The first time I got home to a brightly red lit garage gave me a hell of a fright. The front header was glowing.
    The race ECM I bought from Eric Buell's online shop. And I experimented with a number of mappings I downloaded from the internet and settled on the smoothest riding one. I keep the stock ECM untouched and use it for the bi-annual roadworthy test we endure here in Spain.
    And the bike does run well with some hesitation at low revs.
    Thanks again.

  4. #4
    Senior Member Barrett's Avatar
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    The mechanic told me two sensors that the bike had were disabled, Crankshaft Position and Manifold Pressure.
    Manifold Pressure sensor? No such thing. MAP device 1125 model only. Euro-spec XB manifold vacuum bleed not even monitored.

    When I enabled the CPS I got a trouble code: Causes 0 | Map short to supply voltage / Broken wire.
    NOT a failed sensor. Simply below-acceptable limits voltage signal. Always battery related.

    The mechanic told me two sensors that the bike had were disabled, Crankshaft Position and Manifold Pressure

    Just dying to know how the engine even started with CPS disabled.

  5. #5
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    Well Barrett,
    Just dying to know how the engine even started with CPS disabled. -> He did say the bike won't run without CPS normally, he thought there may be some kind of override.
    Manifold Pressure sensor? No such thing. MAP device 1125 model only. Euro-spec XB manifold vacuum bleed not even monitored. -> He actually pointed to it. I didn't look closely where he was pointing.
    Anyway useful information for me. I'll leave those boxes unchecked and not worry about it.
    Thanks.

  6. #6
    Senior Member Cooter's Avatar
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    The header wrap stuff that insulates the pipe... does exactly that. It keeps the metal at a higher temp (without air cooling) and the bigger swings in heat cycling will make that stainless very brittle. IMO, don't use the wrap. A heat shield with a small air gap is very affective as are good riding jeans.

    A head pipe that glows red is fine. It is literally inches from 63,000 fuel explosions per minute at idle, and 420,000 per minute near redline! Ya, it's gonna get hot.

    You bought a EBR "Race ECM" and then put some random free internet map in it?? I hope you saved the old map. It's the thing you bought.

    Honestly and IMO, it sounds like you're looking for issues that you don't have. I would take the advise from a very wise and good looking forum member on here:

    Quote Originally Posted by Cooter View Post
    ...if it runs well, leave it alone.

  7. #7
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    Thanks for your comments Cooter, noted and appreciated. I'll revisit the original mappings. Cheers, Seb.

    Probably should start a new thread but is the a 12Ss drive belt longer than other XB belts?



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