Boost sensor high voltage zero oil pressure

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by bruce25, Dec 30, 2023.

  1. bruce25

    bruce25 Light Load Member

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    Series 60 12.7 hooked up laptop shows high voltage on boost sensor and shows no oil pressure trucks shuts down. Hooked up manual gauge shows 60 psi of oil pressure. Can't clear codes they are active. I change oil pressure sensor still shows 0 haven't changed boost pressure sensor anyone got any ideas where to start?
     
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  3. Big Road Skateboard

    Big Road Skateboard Road Train Member

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    Did both faults start at the same time? Since you know you have oil pressure, unplug the oil pressure sensor and see if it will run. It should set a high voltage fault for it, but should continue to run
     
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  4. bruce25

    bruce25 Light Load Member

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    Yes both started at the same time and It does run if I unplug it. Wonder what I should start looking at harness? Grounds?
     
  5. AModelCat

    AModelCat Road Train Member

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    Bet those 2 sensors share a ground.
     
  6. bruce25

    bruce25 Light Load Member

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    I think so too I will trace it down and see what I can find
     
  7. Big Road Skateboard

    Big Road Skateboard Road Train Member

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    I would unplug each sensor and check voltage with a meter, across the outside pins of the sensor connector with the meter leads, you should get 5 volts DC across those pins.

    If you don't see 5v there, check wire 416 on each plug straight to ground

    Wire #452, in position Y2 on the engine harness is sensor return. It is sensor return for all of the engine sensors. Since you have no other sensor fault codes, probably not it.

    Wire 416 is your 5v supply to the OPS and BPS I'm betting this is your issue.

    What year is this engine?
     
    Last edited: Dec 31, 2023
    bruce25 Thanks this.
  8. bruce25

    bruce25 Light Load Member

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    Engine is 2002 ddec iv quick update water temp gauge also doesn't show anything. I have traced ground in the harness where all sensors share connected external ground and now everything works. Since harness gets it's ground from ecm I think there is internal issue with ecm.
     
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