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Ignition trouble

fwcole

Active Member
Friend of mine has a 2001 RK with magnetti marelli fuel inj. Bikes not getting any fire. we checked dtc, its putting out 41-CKP sensor intermentant. we replaced CKP and still nothing. Any thoughts would be appreciated.
 
DTC 41 will set if the Crankshaft Position Sensor (CKP Sensor)
signal is absent or weak. I would look for a open or short in the wiring, here's some trouble shooting, it's using a breakout box, but might be a little help in checking out the wires? If you can trace the wires you might find something, it's in that circuit somewhere.

dtc41.jpg


CircuitDiagram.jpg
 
Well still no luck, Weve spent several hours looking for it. If its in the wiring I cant seem to locate it. I did have a couple of thoughts, I was wondering if it was possible to throw that code with a cam pos sensor problem? Is there anyway of testing the ckp that we removed to see if it was bad to begin with? If it was bad then we could start looking for the cause, if it was good then we know it was a different problem altogether. also I forgot to mention this yesterday, we tried to jump the trigger wire and get a spark with dummy plugs and had no luck. I was also reading in the flow chart after wiring issues, the next step would be ecm, im starting to lean that way.
 
All diagnostic roads lead you to the ECM if everything checks out good before, too many techs go there too soon and it's very seldom if ever the problem. I test the CKP and cam sensor by installing a proven one, I think the CKP is just a magnetic switch, if you hook it to a tester and hold a magnet to the bottom it should be closed with the magnet and open with no magnet. I have never tested one this way, maybe one of the electrical experts here can advise you better? If it was the cam sensor the bike should still run, just not run good. When you installed the new CKP how did the terminals look where you plugged it in?
 
All diagnostic roads lead you to the ECM if everything checks out good before, too many techs go there too soon and it's very seldom if ever the problem. I test the CKP and cam sensor by installing a proven one, I think the CKP is just a magnetic switch, if you hook it to a tester and hold a magnet to the bottom it should be closed with the magnet and open with no magnet. I have never tested one this way, maybe one of the electrical experts here can advise you better? If it was the cam sensor the bike should still run, just not run good. When you installed the new CKP how did the terminals look where you plugged it in?

Got to agree with Chopper here have seen too many techs condemn an ECM and continue to throw parts at a problem to get it right
 
Thanks for the help Chopper. The diagnostic flow chart helped alot, and we finally got the problem solved. It was the sensor itself not grounding. The old sensor was bad as far as we can tell, I tested it just like chopper said before he got back to me but wasnt sure. I would still like to know if there is a way to test one, as if the old one is still good it could make a valueable tool.Anyway the surface of the case was cleaned before installation, but the new ckp didnt come with a new bolt and we reused the old one. It was pretty dirty and wasnt allowing a ground.I checked ground from the battery to the ckp and had none so I took the bolt back out, cleaned it, reinstalled it and it worked.
 
I checked ground from the battery to the ckp and had none so I took the bolt back out, cleaned it, reinstalled it and it worked.

The only problem with that theory is the crank sensor does not get it's ground through it's mounting bolt. The schematic clearly shows that.

When you went through the flowchart, what AC voltage did you read when testing the crank sensor. How much greater than 1.0vAC did you read.

The bike may be running now but it is not for the reason you stated.
 
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