Cummins X15 after treatment issues

[Envirotec]

Hi Everyone,

Where do I begin… I’ve been having issues with the after treatment systems on 4 of my tractors. (21, 22, 24, 25).

21 has 426k miles. I figured to have DOC and DPF baked because of the mileage. Did that about a month ago and then threw a code for too much soot in DPF (several quarts worth). Prior to me baking them out, there were no issues or codes with DPF or DOC. Also when I brought DOC and DPF to shop they said filters were in great shape prior to cleaning. They also gave me the sheet with all the tests they did before and after baking. Also, the truck seems to always be in the operating state of after treatment regeneration. No lights on dash but when I plug in with INSITE it shows the turbo running at roughly 60,000 rpm and engine “idling” at 750 when supposed to be 650rpm. I took DPF and DOC off and blew everything out with shop air just to get it going as I had a total of three trucks down (I know I’m throwing a band aid on the issue which I never do). Then about a week later one of my drivers lost oil pressure and I find out there’s 28 gallons of “oil” in the oil pan. Supposed to be 11. Have it at a shop now putting all new injectors and high pressure fuel pump. I don’t think the aftertreatment issue is related, so when I get the truck back, I think I’m going to have to still deal with After Treatment Issues.


22 has 270k miles. Truck for over a year sounded like it was always regenerating. Turbo always spooled high just like 21 above. So I bring to my local dealer which is an absolute nightmare to say the least. The day I bring to the dealer, the radiator leaked coolant so they replaced that along with “fixing” the turbo being spooled all the time when sitting at “idle” 750rpm. They told me the reason for this was due to a worn camshaft. So they replaced camshaft and adjusted valves. Get the truck back, just for it to shutdown on the road due to clogged DPF. So I get DPF and DOC baked. And it runs good for about 2 weeks until I get a code for aftertreatment system. Differential pressure least severe level. I clear the code knowing I’m going to have a bigger problem in my hands in the next few days.


24 has about 300k miles. Truck had a MIL light on for about 6months for DPF differential pressure. Finally brought to a shop and they told me they had to replace the DPF and DOC. This was about 6 months ago. The truck ran for a week or so until the whole “idle” thing like 21 and 22 happened with this tractor too. Take the DPF and DOC off to find tremendous amount of soot like 21. Blow it all out with shop air and code comes back which I was expecting. But the code was for the SCR. I cleared it. It came back. I cleared it again. Then a different code came back for DEF doser voltage. Cleared that. Then came back also. All bandaids I know..

25 has about 325k and had a MIL light on similar to 24 for DPF. A couple weeks ago the truck shutdown while driving (unrelated to After Treatment. Tranny issue). Had to tow back to our yard. While it was down in the shop I took DPF and DOC to shop to bake. I reinstalled (just like other trucks above). Put everything back and light is still on. Also reset filter and DOC in INSITE.


Overall, getting hit all at once here and it’s strange how it is all happening after the DPF and DOC was either cleaned or replaced. I’ve been doing research after research trying to figure it out. Especially, that I’m fairly new to the whole after treatment process. I can’t bring trucks to dealer anymore which forced me to buy INSITE, Quickserve, and Service Ranger. I also have a full time mechanic but he is old school and not tech savvy.

After discovering Rawze and watching all the EGR videos yesterday, I think I might be able to find the solution with the help of everyone on this forum. Just trying to keep our fleet and plants running but this after treatment crap is getting way out of hand. Any feedback is greatly appreciated!!!

Thank you,
Derek