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Thread: Fried ECM and coil

  1. #1
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    Posted this in two places. Hoping for some help.

    Just had my ecm fry for the second time. The first time it took the coil with it. This time the coil is ok, but will probably still replace. The first time I rode it about 3 miles to a gas station b4 she completely gave up the ghost. That's what blew the coil. This time (a little smarter) I pulled her off the road immediately.

    Same symptoms. She suddenly overheats and drops a cylinder. Almost no power.

    I don't want to make another temp fix. Hoping someone out there recognizes this issue. Since the first issue, I switched to the Jardine Titanium Exhaust but have been holding out on opening the airbox until I got a race ecm. So, I may upgrade this time 'round, but there's that nagging suspicion that this may be a symptom of a larger problem and that it may come back and bite me again.

    Maybe a short of some sort? Causing the ecm to overheat and fry, taking the coil with it? The coil runs hot when you fire her up. They told me last time that I cracked the coil.

    Anyone got any ideas?

    Robtk! a.k.a. "Special K"

  2. #2
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    I should mention she's an '03XB9S Lightning with close to 50k in miles. There was a short issue way back 'round 20k that took a couple attempts to fix. Will have to look up the receipts to remember just what the issue was, but I know it had something to do with the ignition.

    Robtk! a.k.a. "Special K"

  3. #3
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    Ok. Looked it up. Temp Sensor went south, but that was after they changed out a couple wires that were chafing. It was throwing a "short" code. First the wires got swapped, then (when that didn't fix it) they swapped the temp sensor and all was well again.

    Also found receipts for another short issue in which my stator was shorting b/c of a loose wire. That took a couple tries as well b/c they told me that it was oil from a leaky line that was spraying on electrodes that was causing my short. But (as I suspected all a long) it turned out to be the stator...

    That's the whole kit and caboodle. Help me Buell Parts Guy!

    Robtk! a.k.a. "Special K"

  4. #4
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    Its a wiring issue somewhere that is still a problem. You need to trace every wire and make sure they aren't rubbed or terminals pulled out slightly. Other than that, without my hands on it, I'm helpless.

  5. #5
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    We're going over the wiring harness, but so far don't see anything serious. How 'bout the voltage regulator??? Could there be an issue there that might be the culprit?

    Robtk! a.k.a. "Special K"

  6. #6
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    Don't rule out anything electrical at this point. Check all grounds also.

  7. #7
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    Here's what one guy posted to my plea on BadWeb:

    Posted on Friday, August 15, 2008 - 09:41 pm:

    The only way I can think that a coil can overheat is when a constant +12VDC is applied with full current drawing through the coil regardless of the normal ignition signals from the cam position sensor that should be present.

    So I would think that if there were a short-to-ground in the signal wire circuit that goes from the suspect coil to the cam position sensor, the coil would overheat because there is no normal interruption of the abnormal constant current being applied. I would double-check all the wiring involved with the ignition circuit very, verry carefully, looking for chafing spots in places where the wire harness might touch ground potential areas.
    Thanks to all for your help so far...

    Robtk! a.k.a. "Special K"

  8. #8
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    Hind sight being 20/20, I thought I might add that this ended up being the #77 connector to my voltage regulator.

    I really hope this helps someone out. Since I've been clued in, I've come across this problem in multiple stories of other Buellers.

    If your XB is pre-'08, you need to replace your #77 connector before it costs you a fortune. At the very least you should inspect it before you replace a voltage regulator.

    Symptoms can include; dimmed headlamps, dead battery, bike running on one cylinder, fried ecm, fried temp sensor, fried voltage regulator, headlamp surges, and/or fried/overheated coil.

    Special K!
    Central Texas Hill Country Hellbuellies
    "I'm a Hellbuelly! What the hell are you?"

    "Be always at war with your vices, at peace with your neighbors, and
    let each new year find you a better Buell."

    --Benjamin FranklinBuelly

  9. #9
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    #77 Connector huh? I've got to get home and look up what that is exactly because i've had 2 fried coils and a fried ECM in the last year.. same bike as you.. i'll def have to change that!!

    Buell Parts Guy, is this something I can order from you?

    Thanks!

  10. #10
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    I don't do any online ordering unfortuantely....



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