DPF derate and warning

Discussion in 'Kenworth Forum' started by Tankeryanker35, May 30, 2024.

  1. Tankeryanker35

    Tankeryanker35 Bobtail Member

    14
    1
    Jul 4, 2019
    Holden, MO
    0
    Good morning! Or is it?

    This morning started like any other. Truck started and was fine, drove fine for about the first mile, then a loss of power, like fuel starvation. I could smell fuel, so I turned around. Withing 1/2 mile the LCD in the dash went from no faults to DPF full/derate/stop engine warning, so of course now I can't do a parked regen.

    My scanner isn't a great one, but the truck set codes for the dpf delta sensor and disabled the EGR. SPN 3251 FMI 16 and FMI 0. Fuel pressures are acceptable, and aftertreatment pressures respond to throttle snaps. Showing just over 60% soot load (160% threshold).

    DPF and DOC were cleaned around 10K miles ago, all 6 injectors were just done 1500 miles ago.

    I disconnected the hoses from the delta sensor and was getting similar pressures out of both hoses, based on feel. There is moisture present in the inlet side, I figure it's condensation. No odor to it.

    The truck has run fine the last two days, it ran fine when I shut down yesterday.

    One thing I thought was odd was the inlet pressure would change with throttle with the inlet hose disconnected. The DPF sensor has thrown some off-the-wall readings in the past, but what got my attention was the drop in power BEFORE a derate was set.
    Thoughts?
    2014 mx13, epa13.
     
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  3. Goodysnap

    Goodysnap Road Train Member

    3,538
    8,486
    Jul 12, 2017
    0
    Just by the description of the fast progression of the DPF soot load and derate, I would suspect a biased DPF pressure sensor or wiring issue to the sensor itself.

    If it’s reached SEL max soot level it will likely need reset.
     
    QUALITYTRUCK Thanks this.
  4. Tankeryanker35

    Tankeryanker35 Bobtail Member

    14
    1
    Jul 4, 2019
    Holden, MO
    0
    The sensor has acted up in the past. It has requested a parked regen after being on the highway for 4 hours, and once completed showed a pressure differential of 930 psi
    This would be the third time it's requested a regen in the 5 years I've owned it, but it progressed too quickly for me to try a parked regen. Less than a mile.

    It needs reset, but I'm afraid of the cost to have someone with Davie come out to me. I don't know any other way around it though.

    As far as the odd power loss and fuel smell, could that be turbo related? I do have a slight exhaust leak before the DOC, but that hasn't caused any regen issues in years...just a bit of smoke while it's burning and the accompanying odor. Fuel filters were both replaced 4 days ago...but no DTCs for the turbo.
     
  5. QUALITYTRUCK

    QUALITYTRUCK Road Train Member

    1,785
    1,735
    Jun 14, 2009
    romulus,mi
    0
    Ask if someone that you know might have program called "eTechnician" After correcting issue it will clear (reset) codes.
     
  6. Goodysnap

    Goodysnap Road Train Member

    3,538
    8,486
    Jul 12, 2017
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    If it was dosing and trying to regen during the event. An exhaust leak ahead of the DOC would most certainly create a raw fuel smell and isn’t helping your regens any.
     
    QUALITYTRUCK Thanks this.
  7. Tankeryanker35

    Tankeryanker35 Bobtail Member

    14
    1
    Jul 4, 2019
    Holden, MO
    0
    That's what I usually get if I come to a stop in the middle of a regen, along with a puff of white smoke. It's not ideal, but it's never stopped it from doing a regen.

    I read somewhere that the fuel smell and choke in the power can be the result of a plugged DPF, but I had practically zero warning. Nothing headed home yesterday, nothing during warmup this morning, and nothing until after I noticed the smell and performance. It practically went straight to derate, with the first DTC coming up being the pressure differential was high, and the scan tool reflects it being way past the regen threshold. The soot level has also not changed in the 45-60 minutes of idle time I've done since, starting and stopping to check different sensors.

    I know the ECM uses that delta sensor to calculate soot load, is there a way to test the sensor?

    Not that it's super expensive, it's a bag of chips compared to what I've dumped into this rig in the last month.
     
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