DEF stop consuming at half tank.

Discussion in 'Ask An Owner Operator' started by Jaytruck87, Jan 16, 2025.

  1. Jaytruck87

    Jaytruck87 Bobtail Member

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    Jan 16, 2025
    0
    Hey guys. I have a DEF issue on my 2019 freightliner cascadia. Dd15. When i got my truck as a second hand, i put premium def into the truck and after a month the supplier didnt have the premium def and i end up using regular def from the bottle, then My truck at first stop consume DEF at quarter tank. So I switch it back to premium def, when I did that I empty out whatever def left inside the tank and put brand new premium def into the tank n fill it 3/4 full, change out def filter, but it still stop consuming at a little over quarter tank. then now even I put in premium def my truck stop consume DEF at half tank. As I drive with the truck not able to consume def it throw out the code for nox sensor and dpf but once I fill it 3/4 full def and drive all the sensor and code shut off. But the problem remain that my truck stop consume DEF at half tank. Please help. Thank you.
     
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  3. AModelCat

    AModelCat Road Train Member

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    Canuckistan
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    Maybe the float's stuck at 1/2 tank but in reality the tank is actually empty? That'd probably throw some NOx conversion faults since there's no DEF there to actually react with the exhaust and catalyst.
     
    Last edited: Jan 16, 2025
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  4. Long FLD

    Long FLD Road Train Member

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    Faulty DEF level sensor?
     
  5. VeritasLogistics

    VeritasLogistics Bobtail Member

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    Sep 25, 2024
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    Yes it's going to be the leveling sensor it's on the tank.I had the almost the same problem it will empty the tank with only 800 miles. Change the sensor problem fix!
     
  6. snowwy

    snowwy Road Train Member

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    Premium def?
     
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