THIS Could get EXPENSIVE...DEF Exhaust Fluid Quality Poor (Cruze Diesel)

thank you oh 2014 Chevy Cruze diesel this is the second one I've ever seen in my life and customer complaints right there on the dashboard exhaust fluid quality pour and it's counting down the miles limiting the speed only has 110 000 miles on the clock uh history of the vehicle I mean they said uh it's been Fairly reliable except for a transmission that blew up it cost six thousand dollars to fix and they have to replace I think the heater and the reductant tank already before a hundred thousand miles and now this so you might be fuel efficient but hey it seems like uh you're not really saving much money overall so let's see what the code is that's stored here in the engine computer and do the diagnosis yep so it is a 2.0 liter Luc diesel and I've already done a full code scan I'm just going to go into engine computer read fault code and we have a closed loop a reductant injection control at limit flow too low history to uh p249d so before we start the car up it's cold right now let's uh do a little research online see what this code's all about and I'm assuming we'll have to do that fluid quality test with the scanner um and then look at our nitrous oxide sensor Sensor One upstream and Sensor 2 Downstream that's what the system relies on to see if you know the scr The Selective Catalyst reduction system is working with the DEF fluid injection so uh we'll see where this goes all right let's just quickly read through the DTC description p249d closed loop reductor injection control at limit flow too low as opposed to flow too high um exhaust knocks concentration lower reduction consumption catalyst efficiency below threshold so you know just read the description uses two nox sensors to control exhaust knocks levels the first sensor is located at the turbo the second is at the outlet of the scr ipt ECM varies the amount of reduction added by varying the reduction injector duty cycle and responsive changes and uh engine exhaust of the levels so these two are here reduction level not in restriction or empty level state conditions for setting the DTC ECM has determined the cattle sufficiency is degraded below calibrated threshold so very generic for four codes you get one sentence that's not helpful um they said this the check engine popped up on a long Highway trip recommend the following parameters required every two minutes during and after each reductant fluid quality test yep an ox concentrations and the EGT sensors so basically what they tell you to do is make sure there's no leaks exhaust leaks the def is brand new the fluid is new and tank is full verify it's not contaminated and then it says remove the emissions reduction fluid injector from the exhaust pipe and do this leak test make sure the injector is not leaking and then you'll make sure it holds pressure and then to do this quantity test where if you look at the quantity test it's supposed to inject 25 milliliters into a beaker that little reductant injector and then you do the fluid quality test so what I want to do is jump right into the quality test and see what these nox sensors are reading see what the car does kind of take it from there so in special functions I'm sorry in actuation test if you go to reductant system reductant fluid quality test by the way on this car it's 2014 and the tech 2 on passenger cars you know there's a transition period between 2010 and 2000 uh by 14 all GM vehicles need you know the OEM scanner is the gds2 which I don't have I can get if I want to but let's see what the thinktool pros can do here all right let's see how she accelerates [Applause] drives very nicely no complaints I love the turbo diesel pull okay now our knock sensor is preheating wait until those wake up and look at the valleys okay so Upstream sensor woke up you're about 100 parts per million so that seems to work fine [Music] I'm waiting for Sensor 2 to wake up I guess we'll just keep driving it around that should wake up pretty soon nothing abnormal yet all right so I think the downstream nox sensor is just disabled it's not heating up at all it's commanded off probably because the code is set so what I'm thinking is let's um let's run that fluid quality test the car is you know fully warmed up now uh you have to shut it off wait until the EGT sensor drops below 90 degrees Centigrade and we'll we'll see what happens all right let's try running it again on engine speed too high okay come on this is where you get with non-oem scanners I guess try again okay it's not it's not kicking me out quality test not requested there we go engine speeding up active so now we watch our nox concentration so raise the 3000 RPM and this can take up to an hour so make sure you have enough diesel in your tank make sure your DEF fluid is full we'll see what happens all right a couple minutes in Upstream sensor is on and concentration is less than 100 parts per million it's fine we're waiting for this Downstream sensor to be commanded on so it's 4 11 p.m right now let's see when that happens all right so four minutes after starting the second test now knock sensor two heater mode preheating so let's see uh see what the concentration is post the scr and we'll see our reductant injector Command right there okay so we see minus 100 then it goes up to should be about the same as the upstream and that tells me both sensors right now are working just fine so right now we have 95 and 55 even though we're not injecting any reductant that's kind of strange we'll keep keep watching this take a snapshot of that why would the concentration be half if there's no reductant unless the injector is leaking so we'll see at some point it should start injecting you know that should be higher than zero all right we're about 12 minutes into the test I still haven't seen the injector inject anything at all interesting to note that the Sensor 2 knocks concentration has been slowly climbing the lowest was 35 this is always around 90. so it was a 35 now we're almost up to 60. how do you explain that I'm not sure but we'll just keep watching the data so it got up to like 75 and then it dropped pretty quickly the Knox concentration two or Downstream concentration why is that I don't see any reductant injector command at all that should be the same as the Upstream is that our issue look now it's going higher again now it's going lower again maybe this reductant injector command data pit isn't accurate it's got to be injecting something look it's dropping like below 30 now hmm well Hallelujah it passed speed zero miles per hour we turned off the check engine light it's happy look Upstream 185 Downstream 25 we're injecting whatever I don't know I really don't know I mean that looks fantastic it's like an 80 reduction in the nitrous oxides all right shut her down take her for another spin scanner for codes again [Applause] sometimes this stuff is just have fixed Vehicles before just by doing the quality test nope no codes it's happy for test drive a little bonus footage just going on a test drive easy cruise at 30 miles per hour this system is really doing well you see our Upstream is 74. our Downstream is like one part per million or zero and once in a while it'll give it a little squirt of urea so when there's not much load it doesn't take much to uh get rid of those nitrous oxides so I'm actually really surprised it's in the single digits Downstream you know can we trust our sensor if we give it give it a little gas yep there's 259 so that sensor seems to be working just fine back down to single digits see it injected more when I gave it more gas pretty neat [Music]

Channel: Pine Hollow Auto Diagnostics

Views: 65,433

Keywords: GM, diesel, emissions, DEF, fluid, quality, poor, scanner, test, reductant, Nox

Id: 4CVR9BR-TbU

Length: 16min 31sec (991 seconds)

Published: Wed Apr 05 2023