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Can’t get rid of P0343 detail code 747: Camshaft timing circuit high input

Discussion in 'Gen 3 Prius Technical Discussion' started by HelloMcFly, Oct 4, 2023.

  1. HelloMcFly

    HelloMcFly Member

    Joined:
    Aug 21, 2022
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    Location:
    Oklahoma City
    Vehicle:
    2011 Prius
    Model:
    Five
    I have a car that will drive for a couple hundred miles, then the P0343 detail code 747 appears and shuts the car off. the code is camshaft timing circuit high input. After the code appears you have to disconnect the sensor and ECU to get the code to disappear then it’s a toss up as to when it will reappear.

    I’ve replaced both the camshaft and crankshaft sensors, and the code continues to appear. Note : I did have a crankshaft sensor alert appear once before.

    i can’t find anything abnormal as timing is spot on, and the wiring is intact and secure. The car ran fine for 6 months before this problem arose out of nowhere.

    Any suggestions as to where to go from here? Any help would be greatly appreciated.
     
    #1 HelloMcFly, Oct 4, 2023
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The output of that sensor is supposed to stay between 0.3 V and 4.7 V at all times (it pulses between the lower and higher value as the camshaft rotates).

    The P0343 indicates that voltage above 4.7 was seen (for four seconds or more).

    One common way that can happen intermittently is if there is some wiring insulation damage somewhere between the sensor and the ECM, and it is allowing the cam sensor wire occasionally to touch something else with voltage above 4.7.

    Other than "intact and secure", what steps have you taken to test the wiring? Have you looked through the steps for that in the P0343 section of the repair manual?

    Toyota Service Information and Where To Find It | PriusChat
     
    #2 ChapmanF, Oct 4, 2023
  3. HelloMcFly

    HelloMcFly Member

    Joined:
    Aug 21, 2022
    34
    41
    0
    Location:
    Oklahoma City
    Vehicle:
    2011 Prius
    Model:
    Five
    Thank you so much Chapman. I haven’t ohmed out the harness completely. When doing the swap hand a year ago I recall seeing a lot of rodent droppings.
     
    #3 HelloMcFly, Oct 5, 2023
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