Fairly new machine with only a few hundred hours on it. It has been sitting for 3 months or so. Ran it today and got this yellow caution: 3516-18 ACU Catalyst Reagent Concentration Low The DEF tank show 3/4 full but I can't remember the last time I put any in there...does it go bad or lose active ingredients or something to that effect? Thanks for the help!
Yes - It has a shelf life in the tank of around 3 months IIRC. Longer if stored in a sealed container. I would suggest to try flushing the tank and refill with new fluid. See attached. The DEF filter will also need replacing. From all the info circulating regarding engines using DEF leaving them parked for long periods is not the best thing one can do.
Thanks for the quick reply! Why do you think the filter needs replaced?
Because the procedure I attached says so........... see Step 10. I'm not familar enough with the system to answer the question why this should be. Maybe someone else can help you regarding that.
OK. Thanks.
The DEF can start to crystallize on the surface of the small filter. Plus, it’s easy to contaminate the DEF while filling the tank on the job site. Logical assumptions. Squishy, Not sure where you are located. It might be something as simple as a frozen DEF tank.
also the DEF filter contains a plug which swells and cuts off the flow if it gets contaminated by hydrocarbons. Not sure if it is similarly affected by degraded DEF.
Why would the fault code say "Catalyst Reagent Concentration." What I seem to recall was that the catalyst part was in front of the DPT and the DEF was injected behind the DPT. Is there something different between the small machine systems than the large machine systems? Also the term "Concentration" would indicate to me that if it is DEF fluid, that it might be watered down and not have enough urea per volume of fluid injected into the exhaust stream. Maybe someone is dumping water into the tank?
Good point, John C. Easy enough to grab the NAPA 3R201 Urea Refractometer and find out. I don't mind spending money on tools, except this one. That tool makes me depressed every time I use it. My best contaminated DEF tank story is from 2012. It was a new University of Alaska Seawolf Shuttle cutaway van conversion. Ford chassis with a 6.7. The def tank was filled to the top with orange soda. The empty two-liter bottles were still onboard. ?? Nobody in the motor pool fessed up to it.
Tengo exactamente el mismo problema que reporta BLANDO Escribo desde Bolivia, agradeceré enormemente los aportes y comentarios que me ayuden a dar solucion al problema.
Sorry I never replied with the solution. The DEF tank sending unit was determined to be bad and was replaced under warranty. I'm actually not sure of the part name, but essentially The whole heat transfer, intake, filter, level sensor unit that fits into the tank from the top of the tank. Took nearly 3 weeks to get it backordered.
I believe they call it the PETU (Pump Electronic Tank Unit).
Just to clarify, Def is referred to as a catalyst reagent. During regeneration and passive regeneration def is injected in and the heat of the exhaust plus the scr causes a catalytic reaction and removes most of what noxious gas left in the process. The way it was explained to me in class one would think that egr isn't necessary anymore I raised that question and couldn't get a answer as to why egr is still being used. I did learn however that the teir5 engine doesn't use egr. I guess the smart people figured out what a dumb mechanic figured.
I was under the impression that DEF is injected into the exhaust stream constantly. The EGR was supposed to burn off the crankcase vapors instead of allowing them to go into the atmosphere. It was also part of the cooling of the firing temperature to reduce NOX. The DEF chemically combines with NOX to make some other chemical.
Not quite constantly. exhaust temps have to be high enough for the reaction and for the nox sensors to come online. When everything is working correctly it's damn near emissions free. Teir4 is good for the ozone, but the irony is that we are burning more fuel and filling landfills with 2 gallon plastic jugs. I would like to see a carbon footprint analysis done with a teir4 final machine compared to a non teir4 machine.
Once the system is up to temperature and the DEF is thawed out, its injected more or less constantly while the engine is running. It uses the NOx sensors to determine how much needs to be injected. Cat is already starting to remove EGR from their engines. Check out the C9.3B. All done in the aftertreatment system.
CAT calls it a DEF manifold. And yes they are prone to fail, but it is covered under the emissions warranty, but they are cat backorderd.
Que problema tiene la maquina? o que codigos aparecen en la pantalla?
This is what CAT is claiming to be the problem, in case y'all are interested to know.
Wow, orange soda? cant believe the guys would do that to the def system. Sometimes I cant tell if the operators are not wanting to work, or if they are clueless or perhaps it was a hate crime, but we got a machine that the def tank was completely full of hydraulic oil. looked liked the Chinese egg drop soup
I have worked in construction for a long time. And I believed that the operators thought break time meant you had to break your machine.
Most likely whoever filled up the tank had no idea what it was for and didn't bother to find out or ask before tipping hydraulic oil into it. I once had a service truck add multipurpose grease to the hydraulic tank on a big shovel, and someone added MPG to the bulk coolant tank on a service truck. Both were easily fixed long-term by making changes to the quick couplers so that it became harder (note I did not say impossible.!) to add the wrong fluid to a compartment. In my experience trying to make things idiot-proof only permits Darwin to develop a better class of idiot.
The 769C truck had a tank next to the cab for the steering system. I was still a newbie and was getting a euclid truck of similar size ready. It had a tank next to the cab also. Only this tank was for coolant and I added 10 gallons of hydraulic oil before I realized my mistake. lots of cascade and 5 hours later I had the coolant flushed of oil.
Are you sure? I've worked for Cat for a few years and always seen it refered to as a PETU in their literature. Unless they just call it that on their bigger equipment and a DEF manifold on the smaller stuff.
You appear to work for the dealer and therefore should know enough to not start posting internal OEM to dealer communications on a open forum. It’s one thing to help or nudge people in the right direction with some good advise and another to post attachments like that. Dealer/OEM employees are in those positions as they should be able to hold themselves to a higher standard and conduct themselves in a professional way - at work and when posting on a forum. But hey what do I know
Yes its possible, I work in the compact construction equipment department, so maybe CAT does call it something else for the bigger equipment.
The two terms PETU & DEF Manifold appear to be used interchangeably whatever the size of the machine. I just found a 3516C Genset where it was referred to as a DEF manifold and a similar generation 3516C Marine engine where it was referred to as a PETU. Go figure.
I've got to tell you Nige, I'm learning a lot from reading your comments on these forums, thank you.
[QUOTE = "LEGO, publicación: 952407, miembro: 96313"] Que problema tiene la maquina? o que codigos aparecen en la pantalla? [/ QUOTE] Estimado Lego adjunto lo solicitado y quedaré atento a los comentarios.
Diego, lo primero que hay que revisar es la calidad de el liquido DEF, para eso hay que levantar la cabina y sacar dos muestras, una directamente del tanque de el def, y se puede desconectar la mangea pequena en el tanque para sacar la muestra y la otra directamente de el modulo de def, que tiene el filtro del DEF, y para eso se necesita un refractrometro de DEF. La calidad deberia estar al 32.5%. O muy cerca de, hasta 34%. Si no esta en este nivel, tu DEF esta contaminado y hay que remplazar el liquido. Pero este es el primer paso. Dejame saber el resultado.
Estimado Lego: Ya hicimos todas estas acciones y todo apunta a la necesidad de cambiar el sensor (manifold DEF). Sin embargo, tomando en cuenta que la calidad del diesel en Bolivia es muy mala y solo es posible la operacion de motores hasta TIER2, el motor de la miniexcavadora es TIER4. Que podríamos hacer al respecto? De antemano quedo agradecido por la gran cooperación. Saludos cordiales.