CCMtruck

Another question. During the scr crystal sublimation test the def pump pressure was dropping as far as 109 psi. Shouldn't it stay around !30 psi?

I've got the dreaded 4094 fmi 1 code. Checked def pump pressure, quality and quantity of fluid. Removed def nozzle to checked spray and measured fluid. Did find several boost leaks that i repaired. Performed scr crystal sublimation test and then a regular regen test and the code is still active. During regens the inlet nox sensor never changed and always read 0 and the outlet nox sensor read correctly. Checked both NOx sensors and are the latest part numbers. Checked ecm and acm software and is up to date. Took unit on road test while monitoring and inlet nox sensor still never read off of 0. Any thoughts?

Thanks for the info. I'll give it a shot

Still struggling to repair this SCR issue if anyone has any ideas. I have even gone as far as reprogramming the ecm and acm. Same active codes are still there.

2014 Mack LEU613 came in with active codes P100000, P208E00, P110386. Removed def doser to test and found hardened def build up in pipe. Cleaned out pipe. replaced def doser and the P208E00 became inactive. Performed a scr crystal sublimation test and P100000 & P110386 were still active. I have tried several different test and procedures to clear out code and nothing has worked. Any ideas?

Update: Just like steeler said. I found aluminum pieces in the inlet side of the ecm cooler plate. Its the simple stuff we forget sometimes.

I will check it today. Thanks for the info.

I need a fuel guru! I'm working on an 2012 LEU613 with an MP7. The fuel pressure starts off great (55psi) but under a load it drops (12 psi). To make a long story short. I have already replaced fuel filter housing, fuel pump and conical injector cups. I have even gone as far as replacing the suction fuel line because i was running out of ideas. I though i had it cured because the fuel pressure returned but slowly started dropping. The engine never dies, it just doesn't have power.