Def light

Discussion in 'Questions From New Drivers' started by Mahertruck, Jul 11, 2019 at 11:59 PM.

  1. Mahertruck

    Mahertruck Light Load Member

    Mar 9, 2017
    Hello everyone .
    My truck freightliner cascadia Evo 2016 the DEF light comes and flashing when I was driving and the yellow Check Engine light turned on for about 20miles then the both lights disappeared DEF and check engine light
    And when this one happened I parked the truck to see if I can get the code
    It doesn't show me code found . just light without code diagnostic
    Is this a serious a problem or normal ?
  2. uncleal13

    uncleal13 Road Train Member

    Apr 9, 2009
    Humboldt, Sk
    Most common issue is low NOx Conversion Efficiency error. Can be caused by a whole host of different reasons. Seeing as you have a 2016, have your DPF filters been cleaned/replaced yet? It may just be an early sign that it is coming due.
    What ever event triggered the error, cleared itself up and the codes cleared themselves when the DEF light stopped flashing and the check engine light went out.
    The MIL light (looks like check engine line but doesn’t say anything on the symbol) will clear itself after three cycles of engine starts and getting back up to normal operating range for several minutes. Usually within a day.
    Nothing to worry about for now.
  3. x1Heavy

    x1Heavy Road Train Member

    Mar 5, 2016
    White County, Arkansas
    You are about to find out where all that cleaned emissions soot went. If you really are concerned have the mechanic shovel that poop out of there. Before your tractor combusts.

    The majority of your trucking future will involve emissions problems in one way or another.
  4. Mahertruck

    Mahertruck Light Load Member

    Mar 9, 2017
    you think if I do engine Regan that's Will help ?
  5. Concorde

    Concorde Medium Load Member

    Jun 29, 2016
    West Melbourne Florida
    Lights are out? Forget about it.

    Probably you just got some bad quality DEF..

    Problems to worry about are low oil pressure and high water temperature. Anything else I don’t lose much sleep over
  6. WesternPlains

    WesternPlains Road Train Member

    Sep 1, 2017
    No that won’t help.
    Need to get the filters in the DEF cleaned.
    Next time the light might be red. You don’t want that.
    uncleal13 Thanks this.
  7. Moosetek13

    Moosetek13 Road Train Member

    Nov 1, 2010
    Burnsville, MN
    I sometimes have a check engine light come on. I have learned to ignore it if it is running fine.
    Often they will stay on for days, or a week, then go off and not come back on. And seldom is there a diagnostic code shown during that time.

    If it is still on at my next service I will mention it. But I won't make a special trip to the shop to get it checked anymore.
  8. if the truck runs fine does what it needs to do doesn't act stupid just drive and get used to the yellow light..
    there's times when I've taken my in it's come out of the shop at 2 hours later another check engine light is come on after they supposedly fixed it..
    I've got used to it or take a piece of black electrical tape and cover it up on the dash
    biggest mistake I made is when I had to check engine light come on when it was only two months old and I spent three weeks in a shop they said it was fixed 50 miles down the road it came on again.
    usually it's up stupid sensor related thing that's more of a headache that hassle than to just ignore it..I've had a check engine light on for over two months now again it regens like it should it goes down the road it starts it doesn't run wierd rolls down road through stop and go traffic. highway speed pulling mtns. it's probably something stupid minor that I could care less about..
    now if it starts acting weird idling weird missing hesitating or something like that or staying in a regen mode and not going away well then it's time to bring it in other than that you just get used to it after you brought these electronic engines since they came out with the afterburners back around two thousand eight or nine into the d e f ones.
  9. exactly indeed
  • Draft saved Draft deleted