Fried ECM and coil

[XBear9S]

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"

[XBear9S]

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"

[XBear9S]

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"

[BuellPartsGuy]

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.

[XBear9S]

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"

[BuellPartsGuy]

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

[XBear9S]

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"

[XBear9S]

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

[2003buellxb9s]

#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!

[BuellPartsGuy]

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

[2003buellxb9s]

That's cool, can you hook up the part number then?

[2003buellxb9s]

or actually, even where i could find it in the manual would be cool..

[Stevenc150]

It's on page 23 of the parts manual. I've got one for your year model. If you don't have it post up your email address and I'll send it to you. I'll get you the part #'s when I get home if BPG hasn't already.

[BuellPartsGuy]

There is 3 pieces to that plug


Connector Assembly - 72234-94 - $4.95

TPA - 72238-94 - $0.95

Terminal Set - Y0126.02A8 - $4.88

[2003buellxb9s]

Okay.. Awesome Thanks Steven and BPG!!

My email is hollatchahomey@gmail.com if you want to send me the page.

Also, where do I find it in the Service Manual... would it just be under Electrical somewhere? I couldn't find anything referencing "77" but to be honest I just skimmed.

And one more thing..sorry.. is this something I could change myself easily once i get the parts?

Thanks again,

-Lee

[Stevenc150]

Parts Manual Sent. [up]

You can find it on Pg. B-17 of the '03 Service Manual. All the way in the Appendix B section. Find "voltage regulator" then trace the wires to Connector 77A & 77B.

[2003buellxb9s]

Awesome Steven, thanks so much!

[Stevenc150]

Glad to help.

[2003buellxb9s]

So BPG, what's the difference between 72233-94 and 72234-94? Looking at the parts manual I can't decide if I need both or if 72234-94 INCLUDES both 72233-94 and 72691-01..

Also, where does one usually order these kinda parts from? Dealership?

Thanks a mill..

[2003buellxb9s]

AND... do you know how much a speed sensor runs? part # 74431-01

[XBear9S]

http://docs.google.com/view?docid=d4rbxwr_20dq5khf

This should cast some perspective on your questions...
Voltage regulator Connector Service kit Y1312.02A8

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


"If you want a bike that catches the eye of a 13 year old girl, get a CBR, Ninja or GSXR. Just don't get caught on NBC's Dateline. If you want a unique, fun to ride motorcycle that other sport bike riders drool over, get a Buell. (That is unless you had a Buell and then traded it for a GSXR) "

---BuellXB

[desotonorsocal]

Hey all,

I know this is an old thread, but I'm trying to dig up info rather than just making a new post. I've been digging in online everywhere and this *seems* to be close to the problem I'm having. At the moment, my '06 XB9CityX is dead in the water. I'd had my temp sensor replaced (fan cutting on/off, CEL on/off, rough running,etc) and it ran perfectly after that for another 500 miles. (Straight riding iron butt style) I parked it and left the state for two weeks then hopped on it to start commuting again and got the same exact symptoms. Before I could go out and buy ANOTHER temp sensor though, I jumped the 1 & 2 pins on the diag plug and got...well, pretty much every code that thing could throw at me. Bewildered, I left the trickle charger on overnight and tried it again. I *quickly* checked some common ground areas and such (I WAS on a long ride and I ran it 100 miles with the bad temp sensor which vibrated the bike enough to have me lose my kickstand; another story) and didn't see anything obvious. Before I wrapped up, I tried the diag again; tons of codes again. Tried to start it and instead of it acting like a bad temp sensor, the bike simply won't start. Ign on kill switch off I get everything except my neutral light (strange). Kill switch on, fuel pump primes as normal. Hit the go button and all I hear is a relay. (Rotated all relays to no affect)

Is it safe to assume I'm another victim of this voltage regulator issue, or worse, could it be the ECM? I was about to buy a new one until I realized they're 300 bucks.

BTW, I'm pretty mechanically inclined (though my background is in cars) but the moto electronics are voodoo magic to me so I've stayed away from them.

Any help, including a Long Beach Buell badass that I will gladly pay money, beer, and my hot-ass sister to, to get her back on the road would be appreciated! I commute 60 miles a day so $80/week in extra gas makes me think almost any price is worth getting her running again!

Thanks guys (and gals if you're out there) for all the input to date. I've been on here a lot, just haven't posted much.
-DeSoto
~Semper Fi~

[Tork]

@ desotonorsocal:
1. Is your battery verified as good? Take your battery to an auto parts store and have it bench tested under load. If it's bad, proceed in replacing the battery while also following the normal voltage checks to make sure the charging system is good, otherwise you may end up eating through batteries.
2. Check your battery cables to make sure they're properly tight.
3. Check your ground points throughout the chassis. Disconnect ground points and check to see if there's any corrosion and grind/sand/file if necessary to restore clean metal-to-metal ground connections.
4. If you suspect issues with your head temp sensor, follow the cable up from where it comes from the engine and runs next to the top of the frame. Rotate and twist the sensor wire around and look for chafing and possible shorting against the frame or other parts of the chassis. I've seen a couple of XBs where the insulation wore away and caused intermittent shorting, erratic performance, occasional check engine light, etc. (same symptoms you've described). To fix the grounding issue, you can take about 4-5 inches of vacuum tubing, slice it lengthwise and slip it onto the temp sensor wire to create a thick rub-proof sheath over it. Can also be done as prevention. Just another thing to check before throwing time and parts at the problem.

[desotonorsocal]

@Tork,

Thanks!
I finally pulled all of the plastic bits to trace all cables (ground, etc, as you suggested) and found nothing wrong. But when I was reconnecting the air/fuel sensor (?) (the sensor on the base of the air filter bottom) I tried to turn it on one more time. Got all the normal lights including the neutral light, and she fired up. I then basically started 'moving/shifting' the harness near the right side of the intake and yep, it would make the bike start and not start, and have the oil & neutral light not come on , etc.

So I've got it narrowed down. When it's running it's got the rough idle vibrating, smells like gas 'dead temp sensor' type symptoms I had when it actually WAS the temp sensor a few hundred miles ago.

I have the ECMSpy cable now so I'm going to 'see what I can see' over the next few days. Just gotta' learn that d**m program first, heh.
Not sure exactly what to do other than that, except that I guess I'll need to look at that/those harness(es) in that area.
-D

1470

[Tork]

Sounds like you've already identified a wiring issue. Following that same method, you can try to isolate the problem by determining which part of the wiring harness causes the symptoms and then use the factory manual wiring diagrams and a multimeter to go through each wire and their associated connector. Check for continuity from connector-to-connector while again moving and twisting the harness to identify breaks or shorts. *Remember to disconnect the battery before doing this.

ECMSPY is not complicated, and the time spent getting familiar with it is worth it, even if you don't get into tuning. It's a great diagnostic tool and will help you understand how the various system components work together. There are many ECMSPY tutorials online and lots of helpful folks here on the forum to help if needed. If you need further assistance, consider opening a new thread so that it gets its own focus and attention.