2014 prostar what might cause code spn 1569 fmi14

Truck is in Derate due to aftertreatment problems. The 1569 is the important part, the FMI 14 not so much.

 

Could be so many things. What is your DEF level? Someone will need a scan tool or computer to get the data, then see what is out of range. There is a pressure sensor before the DPF and 1 after, NOx in and out sensors, temp sensors..... One would think that it would have set some other codes. Upstream problems can cause issues in/with the aftertreatment such as air intake or exhaust leaks.
You could pull out the DEF doser. They can get carboned up or dried/powdered DEF all around it.

 

Post all codes you have along with engine

 

SPN 157 FMI all are for Rail Pressure

All the other codes are likely caused by the high rail pressure. This causes a problem in the aftertreatment which in turn causes the derate.







I don't see a 524285 but I am working off of a Cummins code list which should be the same for J1939.