I very much need your experience about CAN bus. My bike (Ducati) got a serious problem about CAN bus. The first time, my bike shows the "CAN line" error, dead totally on the street.

I found the CAN IC in the dashboard was faulty, so I replaced it, and the bike lived again. I started the crank, engine running about one day, then the error "CAN line" came again!

Then I replaced CAN IC again. This time the engine was running about 5 minutes and the error appeared again! I checked wire loom, and all of them were fine. No shorted, no problem.

Someone told me about the ignition coils destroying my dashboard by EMI/ESD/EMF.

  • 2
    Is there a reason why you can't just take the bike to the nearest Ducati certified mechanic? You didn't buy an "el cheapo ricer," Ducati stancs behind their bikes & a licensed mechanic will have far better tools to trace down the fault than we can walk you through based on electronics theory, without knowledge of the "bad habits" of your particular model. ... and this question is quite "off topic" according to the rules in How to Ask. – Robherc KV5ROB May 22 '17 at 5:19
  • The Sorry about the rule ! I did take my bike to Ducati dealer, then they asked me to replaced a new dashboard (1200$), I agreed! The bike had worked for a week before the error appears again , I contacted my dealer but they said they have no idea, they ignore me now. I mean 1200$ for the bike running for a week is unacceptable ! I have to fix it by myself! Anyway, sorry about the rule ! – Lê Trung May 22 '17 at 9:31
  • What is the question? – Peter Mortensen May 27 '17 at 11:02
  • Can this be migrated to mechanics? I think I have a good answer – Terry Gould May 27 '17 at 12:35
  • @TerryGould - "Can this be migrated to mechanics?" To request that, you would need to flag the question for moderator attention, select the "In need of moderator intervention" option, and explain the request. HTH. – SamGibson May 27 '17 at 18:11

What makes you think it was the CAN bus transceiver at fault, could it be a coincidence that the intermittent fault disappears after you replaced it?

I would do the following to determine the fault or to see what is causing the IC to fail:

Scope the CAN bus H&L lines - They should be a near perfect mirror image of each other.

Not really necessary but if your scope doesn't have a decode function hook up a CAN bus analyser. It can help to view real time CAN messages and you can see what was the last node to transmit.

Then unplug all suspect devices such as ignition coils and any devices on the network which aren't the two termination nodes. (Usually the Engine and instrument cluster on cars and trucks, not too sure on bikes)

Try to invoke the fault by operating various items, starter, lights etc etc while monitoring the CAN signals. If nothing happens plug each unplugged item in one by one and then operate various items, starter etc. Also wiggle the wiring and pull on each connector.

Keep doing this until a fault appears or you notice an anomaly on the CAN signals

  • Thank you for your reply. I used the multimeter to check the old IC with the new IC, they're differently! I know I have to use the scope to check my CAN system, but I don't have a scope ! Could I buy a USB Scope cheap to check it ? Or Could I use TVS diode + Common mode choke for dashboard, ECU, ABS ... ? – Lê Trung May 28 '17 at 2:12
  • I wouldn't add any extra components as even if they do solve the problem they're only masking it rather than fixing it. There's obviously a problem that needs addressing. What CAN transceiver IC does it use? – Terry Gould May 28 '17 at 14:18
  • The CAN transceiver is TJA1040, I very sure the can ic is faulty, I replaced 3 Can IC, then I test them with multimeter, they are different with the new IC – Lê Trung May 29 '17 at 15:28
  • Like I said try to find the fault, a cheap USB scope should be good enough. If the transceiver goes down again I would swap it with a SN65HVD1040A its directly compatible and is very resilient to faults. – Terry Gould May 29 '17 at 20:37
  • Could I usr SN65HVD1050 ? Because I can't find 1040A. Thanks. – Lê Trung May 31 '17 at 4:24

DO you know how CM impulse current from spark induces V overvoltage in inductive cables? Then you ought to know why CM chokes are needed.

Is it resistance carbon wire to plug or pure copper? Why does this make a difference?

  • Sorry, I still researching my problem, so I am very amateur about electrical, please tell my why/how ? – Lê Trung May 28 '17 at 2:18

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