Have I fried my ECU???

Discussion in 'EFI/carb' started by smoke_tard, Aug 22, 2010.

  1. smoke_tard Husqvarna
    C Class

    Ok I might have done something real Stupid tonight...:banghead:

    I was Wiring in my new Power Commander V and Autotune on My 2009 SM610 I.E. I was looking for a good power and ground source for the switch 12V power wires for the Autotune unit... The bike was running while I was probing around for a good switched power source when I might have fed +12v to the Green Black wire on the coil side of the power relay... This is the ground side of the coil on the relay that controls the fuel pump, ignition coil etc... this wire comes directly from the ECU...

    Now the Neutral light indicates a fault (three flashes then solid for a couple seconds then three more flashes and solid...) The bike will crank over but the fuel pump does not run and there is no spark. The Power relay is not switching. The positive side of the coil is hot but there is no ground for the coil. I disconnected the ECU from the harness and connected the ground side of the relay's coil to the negative side of the battery and the fuel pump ran. I believe the problem is that the ecu is simply not bringing the negative side of the relay coil to ground.

    How do I clear this fault? I have disconnected the battery for an extended period of time (couple hours) and when I reconnect the battery the error is still there.

    Is it possible that the fault code gets cleared and it will function properly, or did I do permanent damage to the ECU???:excuseme:

    Any Help is greatly appreciated...

    Thanks
  2. seymore Husqvarna
    AA Class

    Location:
    Boise, ID
    I know that sinking, sick to the stomach feeling of; what did I just do!:banghead::banghead::banghead:

    You're likely correct in thinking you fried the output transistor that grounds the relay coil. If that is the case you probably need to spend the money and get a new ECU ordered.

    The chances of being able to successfully at un-pot the ECU and repairing the fried parts is fairly slim and time consuming.

    The error code is likely from sensing low injector and coil current since there is no power to them.

    As far as your original tasking of finding a good switched 12v for the AT module, the powered side of the ignition coil works well since it's only powered when the engine is running (and the ECU is fried).
  3. smoke_tard Husqvarna
    C Class

    yep... it's official, I fried it... Oh well, I ordered a new one from Hall's (only $234)... could have been worse...
  4. hotducati Husqvarna
    B Class

    how did you test the ecu if it was fried? mine does the same thing, but my relay is clicking....