| Author | Message | ||
     Al_lighton |
I swear to god, the damned head temp sensor on Buells is the source of more gremlins than any other component. Someone needs to go to the factory where these things are made and do a freakin exorcism. I've seen many a bike that wouldn't run right that was eventually traceable to a bad sensor. I've seen failures on a bunch that haven't triggered the fault light. I'm ready to amend Al's two rules of Motorcycle mechanics to add a third rule: 1) All problems are grounding problems until proven otherwise. 2) All problems are related to the last thing YOU worked on. 3) ALL OTHER FAULTS ARE THE *$*^%&$(%*)&$&$)* TEMPERATURE SENSOR!!!! We just spent a few hours trying to find a weird problem. A bike started running rough. Then it wouldn't start at all, and the ECM went into Fault blink mode all by itself without putting in the shorting dongle. The codes, most of them, but not ALL of them, in succession, would blink out. The fan would run, the fuel pump would cycle, and the fan wouldn't go off even with the key out. Changed the ECM, no go. Checked the fan, no go. BTW, it sure would be nice if Buell put about 2" of slack on that fan connector so you can actually mate and demate it without removing a bunch of stuff. Buzzed out all the power and grounds to the ECM, all checked out. Finally disconnected the temp sensor, problem fixed. Reconnected it, problem stayed fixed. I suspect it was an internal short in the sensor, which gave the ECM an abnormal short to ground that simulated shorting pins one and two to ground on the diagnostic port. All it took was moving the wire around to "unshort" it. There was no external damage to the wire or sensor. Might be in the bike harness, but didn't see any nicked wires. Wasted a few hours of time finding this. If you don't have a spare temp sensor, you might want to consider keeping one around. Its just one of those things that is usually easier to test by unplugging the bad one and plugging in a good one. Anyone else have any good problem symptoms that were eventually traced to a bad head temp sensor? Al | ||
| Iamike |
Al- Welcome to the world of electronics. I've had more bizarre things happen that make no sense, then all of a sudden everything works. The wierdest was the radio that wouldn't transmit when the engine was on. Finally realized the rear window defroster grid was bringing the RF back into the vehicle and screwing up the 2-way radio. Fixed it by switching from a 1/4 wave antenna to a gain antenna. My only sensor problem was when I broke the lead inside the boot at the top of the sensor. It was intermittent but at least it turned on the engine light and gave me a code. Otherwise I may not have been riding that bike anymore. | ||
| Monkey |
Cycling Fuel pUMP,Fan that runs on when cold,etc.---Al, your timing could only be better if I had read your post yesterday, as I had to push my new Uly to a buddies house after First Thursday Bike night here in Minneapolis I rode over to Bob's Java Hut to hang out with the usual suspects and swap lies...I went to leave-and the bike had cooled down by this time and I went to start my bike -well the fan started running, the red idiot light started flashing like it was hot (not!)and of course it wouldnt start! then the fuel pump was cycling on and off to boot! I had to pull the battery ground batt. cable to keep from draining the battery (which was getting warm by now)I did have two "Bros" with bandana's come over to help out to no avail.So I had to push it just a few blocks to my buddies garage and he gave me a ride home...this is the kind of thing I ran into with my tube frame buell-and traded it off, as I got tired of being left by the side of the road! (several times on the X-1!!) | ||
| Monkey |
PS-where is the temp sensor,so I can check it out? pps-have you heard of a problem with the wiring harness where it runs up the neck of the bike and gets pinched between the frame and fork tube? I could have sworn I saw something on this (somewhere)but cannot find it in the search now-I posted a question on this but no response-argh! THX! | ||
| Al_lighton |
The head temp sensor is in the center of the rear head. A single braided insulation wire comes out of it, and there is a rubber boot on the top of it. Two long screwdrivers can be used to slide the rubber boot up the wire. To remove it intact, you'll need to take a deep dish socket (1/2" I THINK, ping me at A.S.B. and I can look at mine) and dremel a 1/4" wide slot out of the side of it so that the wire has a place to go. I would be willing to bet money that your fault is on that line. It may not be the sensor itself, but I'm pretty sure it is that line getting shorted to ground somewhere, likely in the sensor itself. Al | ||
| Sparky |
If it's a metal overbraided wire, that might be the problem. All it takes is for one tiny strand to break and pierce the insulation causing an intermittant short. Seen that a few times around the rocket factory. | ||
| Monkey |
 Just received the verdict on my bike; Bad ECM (!) covered under emissions warranty!! cost;$0 !! | ||
| Monkey |
 Update-the ECM did not fix the problem-they don't yet know what is wrong-but now the bike will behave normally upon start-up only to shut down a couple of miles down the road....Hmm? The diagnosis continues. | ||
| Sgthigg |
Al, If you need to remove an replace the whole thing what does it take as far as tools and procedure? I got my bike back from the dealership about a year ago and noticed it was all chaffed and exposing wire. I taped it and put a wire protector around it its been fine eversence but I got a feeling it wont be long till she acts up and I will need to replace it. So if you have any info that would help out alot. Thanks |
