| Author | Message | ||
     Mriulvr |
04 Buell XB12s 47.5k well maintained (i.e., preventative maintenance) since I bought it eighth years ago. Garage kept, daily driver with a few long trips, never tracked or abused. Only issues I have had are the relays (see #9 below), clutch ramp broke and repaired, and the infamous 77 connector problem (I think that is the right one). Replace handlebars about five years ago after someone apparently knocked it over in the parking lot and bent the bars, replaced the Jardine exhaust with a Hawk and tuned, tail chopped and put in an XBLight integrated tail light, and breather reroute. The tach works about half the time while riding. The other half it bounces around between a few rpm high to 3000 rpm high but not while idling or reving in neutral. It started after doing accelerations at each throttle position with wideband O2 sensor when tuning. Does it whether on the wideband or NB and was fine before that while using the LC2 O2 sensor. Nothing was changed or modified before it started. I have troubleshooted everything I can find (on this forum and others, manual, wiring diagrams, etc.) and can think of so I am hoping someone has an idea I haven't considered. What I have done so far. 1. Checked logged rides and RPM is normal, doesn't show the bouncing that the tach shows, 2. Checked wiring for any bad insulation/exposed wires, 3. In the process re-ziptied wiring, 4. plug wires are only about a year old, 5. spark plugs are new (started prior to new plugs), 5. cleaned connector to coil (I understand the tack is determined by the coil) as well as pretty much all other connections, 7. I cleaned and treated all earthgrounds (https://www.buellxb.com/forum/showthread.php?54706 -Fixing-Earthing-Problems-Why-and-How) including adding the ground from the battery and to the coil, 8. Battery is good and connections are tight and clean, 9. Had a relay that was going bad so replaced all three. 10. Checked and cleaned or replaced fuses and the fuse box connectors while cleaning the earthgrounds. 11. Checked and re-siptied wiring under the airbox, thinking I might have some RFI interference. The tach works fine while idling so do a wiggle test of the wiring doesn't seem like it will help. I am starting to wonder if it is the tack itself or an exposed wire somewhere that I haven't found. Anything else anyone can think of? | ||
| Tpehak |
You can check if tachometer signal is good with oscilloscope on the tachometer signal wire from the cluster plug. So if Bluetooth dongle shows correct RPM with no bouncing it means the ECM has correct RPM signal. RPM signal to cluster goes from ECM (at least on 2009 Buell XB, so check wiring diagram). So it is might be bad ECM too. If you see bad signal on cluster plug you can connect oscilloscope to RPM output wire on ECM plug and see the signal there. If the signal on ECM plug is good it means the problem is the wire. If bad it means the ECM is bad. If the signal in the cluster plug is good it means the problem is likely inside the cluster, or on the cluster ground wire. (Message edited by Tpehak on July 01, 2019) | ||
| Mriulvr |
Tpehak, thanks. First, besides not having an oscilloscope, that would be hard to do when on a ride, which is when the RPM issue occurs. Second, what wood a "good" signal look like and what would a "bad" signal look like? I found the hertz for the speedo in the manual (7-56) but nothing for the tach. I have also not had a 35 error code for the tach, that I know of and I did check. The manual says to use the Digital Technician (Part No. HD-44750) to test the tach but I am not too enthused about the idea of an HD tech touching my Buell. I will take a closer look at the pink wire from the ECM to the tach and the connections at both ends again. | ||
| Tpehak |
You can buy digital tachometer on eBay for $5-$10 and connect it to the tachometer wire. If it works OK the problem is likely in the cluster. If it works the same the problem might be ECM. | ||
| Mriulvr |
So I started thinking on my ride home yesterday, which is scary in and of itself. I have gone through the electrical system, checked, cleaned, and treated all the earthgrounds and nearly all the connections...except the ECM! So last night I pull into the garage, pop the seat, remove the ECM connections, spray liberal amounts of CRC 2-26 into the ECM sockets and each of the holes for plugs, let it sit for a little while and do its thing, clean up excess, and plug them back in while still wet. Then I did the same to top of the plugs, where the wires go in. Today I am on the way to work and tach seems to working fine then starts the bouncing again, but not as much, then the tach settles in and no bouncing for the remaining 30ish miles of my 35 mile ride. Hoping I didn't just jinx myself, but looks promising or at least was a part of the issue. I hate electrical gremlins. | ||
| Mriulvr |
So, apparently did jinx myself with the last post. Tach still bounces, and sometimes sits at 0 RPM, and at other times works fine. Thinking of opening up the dash and trying to clean with electronics cleaner. As I previously posted, the RPM output from data logging is correct so it doesn't seem to be the ECM output. The only other thing I can think of is the spark plug wires are bad, but they were replaced with new one last year and the plugs this year. Doesn't seem to be an issue other than annoying but is now a driving me nuts and I am taking it as a personal challenge. If anyone has any other ideas from what I have done, see previous posts, I would be glad to hear them. | ||
| October_v |
I took my '07 out tonight after work, had the same thing happen for a few miles. Following this thread. I so hope I dont have to drop 300 for a new ecm. | ||
| Audiowize |
Your spark plug wires are not bad. Bad spark plug wires would make the bike run poorly, but this hasn't been a complaint of yours. The ECM gets a signal from the camshaft position sensor then sends that information to the cluster. If the camshaft sensor or associated wiring has issues, your bike will run like crap (I've dealt with this). The tach signal is sent down the pink wire from the ECM to the cluster. With the cluster and ECM unplugged, you can test the robustness of the pink wire with a test light. I would also look for the green stains of corrosion. This wire doesn't have to carry much in the way of current, but a corroded connection will garble up the signal coming from the ECM. If I had your bike in front of me exhibiting these symptoms, the first thing I would do would be to loosen and re-tighten all of the ground connections, including the bolts between the tankframe and the back frame spars. If that didn't help, I would swap a cluster off a different bike to see if it exhibited the same symptoms. The recommendation to look at the waveform on a scope is a good one. If you can get this problem to happen with the rear wheel in the air and spinning (carefully), you could probe the pink wire at the ECM end and the cluster end. Different signals would indicate a problem with the wiring itself. With the lack of dealers and servicing available for these bikes, it would be a good idea to make friends with someone who has a scope or lots of spare parts for occasions just like this! | ||
| Shoggin |
Since your Datalog shows the proper signal, that is what the ECM is seeing. The CPS is providing the right signal and the ECM is processing it correctly. All good. So check: Signal wiring (pink) , ground to the cluster (black) or cheat by replacing it with the cluster from your '07 to see if that fixes it. The speedo signal (not tach, speed..) may be different from the '04, I forget the cut-off for that) | ||
| Arry |
I'm way late to respond to this, but I had the "tach bouncing" problem a couple of years ago. After just dealing with it for a year, I started having other intermittent issues (spontaneously dying, then starting after sitting a few minutes, and running just fine) I had checked everything I could think of, and finally broke down and spent the money for a new ECM. That fixed everything. Just wish I had went through the supplier (can't remember their name), instead of a Harley dealer. | ||
| Arry |
IDS is the supplier. idspd.com I went through a harley dealer, and had to bring my bike to them, so they could install and flash a program into the new ECM (this is the only way they would work with me). Of course, they botched the job, and I had to bring the bike back (I think they didn't get the TPS reset correctly the first time. | ||
| Tpehak |
I'm surprised you have a dealer can work on your motorcycle. There is not a single Buell service here is Washington State. Harley Davidson dealers do not work on Buell here too. When I was looking for someone to diagnose and check my Buell XB ECM I found none. I ended up buying blank ECM on eBay and flashed it myself with ECM droid and necessary EEPROM file Buelltooth shared with me. (Message edited by Tpehak on November 28, 2019) | ||
| Arry |
I guess this actually was over 4 years ago, so I don't know if that dealership will still work on Buells. The shop that I used is in the Portland, OR area. I shouldn't bad mouth them, as I didn't have a way to do it myself. | ||
| Mriulvr |
I have contacted IDS and am considering replacing the ECM. Thought about buying a used one and flashing myself but am a little concerned about second hand electrical parts. | ||
| Nik |
I had the same tach bouncing issue. It started about 3 years ago and a year and summer of 18 other issues like what Arry described. I also had a rogue o2 sensor code. http://www.badweatherbikers.com/buell/messages/327 77/811336.html?1529681893 TL/DR it was the ECM. Specifically it was the solder joints from the PCB to the connector pins. A new one from IDS fixed everything. | ||
| Europachris |
I've been dealing with this problem on my '06 XB12Ss since 2012 on and off. I checked chassis and harness grounds and futzed with the connector to the cluster. Originally it was "solved" by application of some silicone grease to the cluster connector, which would last a few years before the problem came back. I believe I even replaced the grounds and tach wire connector pins at one point. Anyway, fast forward to the present day - the tach problem has become persistent and much worse and nothing I did at the cluster connector made a difference. I was out riding the weekend before last and thinking about what else to check (plug wires, etc.) that might be interfering with the tach signal. On a hunch I stopped in a little turnout, removed the seat and disconnected/reconnected the ECM connectors. I got back on the road and voila! Problem solved.....for two days. However, it gave me the clue I needed and that I'd maybe been chasing this problem at the wrong end of the wire for years! I started searching for more info and came across this post as well others calling out the ECM as the problem. I wasted no time in gaining access to the solder joints, finding the tach pin as well as several others with cracks. The old solder was removed, new "real" solder applied and the access hatch re-sealed. I hope to test it later today if it doesn't rain. It hasn't rained for a month in any meaningful manner despite predictions of "inches" of precipitation, so my luck it'll pour out of a sunny sky, LOL. I have complete faith in the cause being found and the repair being successful! Thanks, everyone. Chris | ||
| Europachris |
Well, unfortunately the solder job didn't fix the problem.  However, it did turn up an interesting clue: I started the bike on the side stand and everything was fine, but as soon as I sat on the seat the tach started bouncing. I get off, it stops. I repeated the test several more times with the same results. And no, I'm not that fat. Even firm hand pressure would do it. It's weird. Wiggle testing didn't help much but I did get the bike to die once, which surprised me. I couldn't get it to do it again. Time to look more closely at the wiring and grounds and frame bolts. I do have a 'scope to look at the signal integrity as well. It's possible my solder job didn't "take", but I have been building audio gear for 30 years, both PCB and point to point, tubes and solid state, so I'm pretty confident in my skills. [Edit]: One last symptom - when the tach starts going like an epileptic at a Pink Floyd concert, the Check Engine light will start illuminating randomly. However, there are no trouble codes being stored and the engine runs perfectly. Stay tuned.... (Message edited by europachris on July 12, 2021) | ||
| 2cylinderbill |
I saw another thread here where folks talked about the effects of the seat on the ECM in terms of interference, i.e., the seat touches the ECM and when weight is applied, flexes it enough to cause electrical issues and ultimately complete failure. The thread talked about some custom mounting hardware for the ECM so it is not interfered with by the seat. It was fairly recent but I don't have time right now to search for it. On my 08 Uly, the ECM floats freely under the seat. It was like that when I bought it so I thought nothing of it. Once, when I reinstalled the seat, I started getting weird electrical problems where the bike would stumble and cut out, dash going crazy. When I pulled the seat, I noticed that the ECM would be interfered with where it was sitting. I must have inadvertently moved it. I moved it back to where it always lived and the problem went away. I left it unattached (held only by the wiring harnesses) even after reading the thread I mentioned above and everything works just fine. While I don't recommend having it float freely, it works for me. I learned that I just need to be careful it stays unobstructed by the seat. | ||
| Europachris |
PROBLEM SOLVED!!!! Thanks for the info on the seat, 2cylinderbill. I did look closely at the seat and ECM area and saw that the seat pan had a nice hollow area to clear the ECM and wiring harness/connectors. There was an even layer of dust that showed that there was no contact in that area. However, there was contact between the seat and the battery cables. To make a long story short, pun intended, I found that the vehicle harness was laying on a ground wire as it routed past the battery. The ground wire had worn through the harness cloth tape and wire insulation on, tadaa! the pink tach wire! So as it ran and vibrated it caused all sorts of garbage signals and explains why when I sat down on the seat yesterday it caused the issue to appear and disappear as it moved the ground lead just enough. The bike does seem to run a bit better since I soldered the ECM pins but it isn't anything major, just a little snappier maybe. Nevertheless, I'm very happy I found a true cause to the problem, finally. | ||
| 2cylinderbill |
Glad I was able to provide a clue. Nice work finding the real issue! | ||
| Mriulvr |
Wow, I just realized that I originally posted this two years ago. I haven’t ridden much in the last year with the craziness of working from home but am still having the tach issue. The issue only happens while riding after warming up and over 3k rpm. I haven’t had any error codes and bike runs fine but that little spastic tach needle is driving me nuts. I hate little issues like these and am a little OCD about figuring it out 🤬. Doesn’t seem to be a serious issue, until it is a serious issue when I am on a ride in the middle of nowhere or in the middle of rush hour traffic. Like Europachris, I have done the wiggle test at the ECM and other wires under the seat as well us behind the windscreen with no issues. As previously mentioned, all grounds have been cleaned and treated, checked and treated connections at the cluster. I am going to check the seat clearance to the ECM and battery cables as well as the pink wire continuity and connections and recheck for wire wear. I have done some retiring and routing under the seat for my LED taillight and my WB O2 sensor so I could have inadvertently caused a worn wire insulation.🤞 Will report results. | ||
| Mriulvr |
Did a quick look under the seat and behind the windscreen and did not find any worn wires. Pulled the connector at the ECM and cluster and did not find any corroded connections. The pink wire seems fine. So no fix yet but will do a more thorough check of wires when I can. Does anyone know what input the ECM uses for the tach? Tried looking at the wiring schematic but my electrician skills are limited. Maybe the issue is with the input and not the output? |
