DD15 low NOx conversion efficiency and bad DEF Quality

http://www.thetruckersreport.com/tr...ck-engine-and-maintenance-light.288908/page-1

See above. Same issue on my 2012 Cascadia DD15 engine. In short, eventually needed a new onebox. Got it while it was still in warrantee. 600k on mine.

 

Just wondering how many miles / hours are on the engine?
Now that these have been out a few years we may see this issue more often.

 

I had same problem in 2011 Cascada in the end they said the DOC filters Diesel Oxidation Catalyst were bad. They are built into the Onebox system and can't be changed like the DPF filter. They did try a special cleaning mode that Freightliner can run. Its basically last chance try. It cracked my DOC filters or something was rattling after they did the cleaning. The emissions box was no good. A new emission box was $12,000 installed. I got out of owning my own truck at that point.

 

Ouch $12,000 I think that box would of been history.......

 

There's a member on here named @mhyn that's technically knowledgeable with his freightliners. He's got the diagnostic software I believe.

 

Yup my total cost would've been near the same (had it been out of warranty). ~$12k. I opted for new filters too at the time.

 

Your SCR module (1-BOX) has failed and it's not converting NOx internally.
Disconnect your DEF metering injector and perform a low temperature ATD and verify the NOx are working. They shouldn't be more then 50PPM apart and that will verify your inlet and outlet NOx sensors are not drifting. If your DEF air and DEF air pressure are within range and your DEF nozzle is spitting out 108-132 mL of fluid during a quantity test then your SCR module (1-BOX) has failed internally and you will need to replace it.

 

That is the DOC face plug cleaning and it's a 5 hour regen. That is performed when you have a noisy SCR module assembly (1-BOX) due to a plugged DOC face. If the DOC pressures start off high and stay high on a parked regen and the SCR module is noisy the DOC face cleaning procedure is performed to clear up the face of the DOC, but if your pressures start off low and stay low then you have a internal crack inside the SCR module and it will need to be replaced regardless.

 

I have seen good used 1-box for 4500 greens on ebay..

 

hi. what is the mileage of your truck? any modification done with engine soft? hp upgrade ?
DOC and the SCR are designed to last lifetime of the truck. Excessive heat kills them. That heat comes from leaking injector usually ( and if your engine has tuned up more than 600 hp). So if you have scangauge installed in your truck and monitor DOC temp you will be ok. its a good practice to do idle balance test every 2-3 mounts