SPN 4364 FMI 18?

[Billdozer2]

Hey guys, I got a check engine light on and curious if anyone has seen this fault before.

Fault is SPN 4364 FMI 18 - Aftertreatment SCR Catalyst Conversion Efficiency - Data Valid but Below Normal Operating Range - Moderately Severe Level.

I have access to Quickserve and Insite. According to the diagnostic tree on Quickserve, first step is to check for other codes active or inactive. There are no other codes in the system.

Truck is a 2013 Volvo 670 ISX 2250 (400ST)<----I know. It's a used big name company truck. Just under 370,000 miles.

Truck is stock and runs fine. Boost is normal. All temps are normal. Fuel mileage is normal.

I haven't checked anything else out yet. Just curious if anyone has seen this before and could give me a point in the right direction to cut down on diagnosing time.

Hopefully this is the first and last time I have to deal with after treatment issues, as I plan on going Plan C but I do not have anywhere to do it right now.

Thanks guys

[Unilevers]

this means that the nox reduction from the aftertreatment inlet and outlet nox sensors is not high enough. in otherwords the scr isnt working. if you drive it long enough with this issue it will get steadily increasing derates until your down to 1000RPM.

Most of the time it is a bad nox sensor. it can also be a bad scr injector, bad urea, urea crystals in the decomp tube, wrecked SCR, bad dosing pump/plugged filter, or a leak in the urea system.

force a regen and compare inlet to outlet nox - when the scr is dosing the outlet nox should be much lower than the inlet nox (outlet should run about 25ppm).

[trdodd07]

(05-27-2016 )Billdozer2 Wrote:  Hey guys, I got a check engine light on and curious if anyone has seen this fault before.

Fault is SPN 4364 FMI 18 - Aftertreatment SCR Catalyst Conversion Efficiency - Data Valid but Below Normal Operating Range - Moderately Severe Level.

I have access to Quickserve and Insite. According to the diagnostic tree on Quickserve, first step is to check for other codes active or inactive. There are no other codes in the system.

Truck is a 2013 Volvo 670 ISX 2250 (400ST)<----I know. It's a used big name company truck. Just under 370,000 miles.

Truck is stock and runs fine. Boost is normal. All temps are normal. Fuel mileage is normal.

I haven't checked anything else out yet. Just curious if anyone has seen this before and could give me a point in the right direction to cut down on diagnosing time.

Hopefully this is the first and last time I have to deal with after treatment issues, as I plan on going Plan C but I do not have anywhere to do it right now.

Thanks guys

I had that issue a few months back on my 2250. It was my NOx sensors and a split in the aftertreatment wiring harness somewhere.

[Billdozer2]

(05-27-2016 )Unilevers Wrote:  this means that the nox reduction from the aftertreatment inlet and outlet nox sensors is not high enough. in otherwords the scr isnt working. if you drive it long enough with this issue it will get steadily increasing derates until your down to 1000RPM.

Most of the time it is a bad nox sensor. it can also be a bad scr injector, bad urea, urea crystals in the decomp tube, wrecked SCR, bad dosing pump/plugged filter, or a leak in the urea system.

force a regen and compare inlet to outlet nox - when the scr is dosing the outlet nox should be much lower than the inlet nox (outlet should run about 25ppm).

Thanks for the info Unilevers! I was thinking a bad nox sensor at first but figured I would have another code. Something along the lines of "Sensor 1 Fault Plausible". But that's my automotive brain working. I'm not sure how similar a truck flags faults compared to a car.

I'll give it a check out and update if I find anything.

[overshot]

(05-27-2016 )Billdozer2 Wrote:  Hey guys, I got a check engine light on and curious if anyone has seen this fault before.

Fault is SPN 4364 FMI 18 - Aftertreatment SCR Catalyst Conversion Efficiency - Data Valid but Below Normal Operating Range - Moderately Severe Level.

I have access to Quickserve and Insite. According to the diagnostic tree on Quickserve, first step is to check for other codes active or inactive. There are no other codes in the system.

Truck is a 2013 Volvo 670 ISX 2250 (400ST)<----I know. It's a used big name company truck. Just under 370,000 miles.

Truck is stock and runs fine. Boost is normal. All temps are normal. Fuel mileage is normal.

I haven't checked anything else out yet. Just curious if anyone has seen this before and could give me a point in the right direction to cut down on diagnosing time.

Hopefully this is the first and last time I have to deal with after treatment issues, as I plan on going Plan C but I do not have anywhere to do it right now.

Thanks guys

Yep, I had the same fault. Rawze told me it was most likely the outlet NOX sensors.
But I don't have to worry about that stuff anymore, thanks to them boys from GA.

[jimeneztrans84]

How long do the nox sensors usually last?

[Nilao]

+\- 200k miles is the expected life cycle of a NOX sensor.

[jimeneztrans84]

Thanks nilao!! Mine is currently throwing this code and might be the nox outlet. Already changed the inlet nox...

[JMBT]

Jimeneztrans84, also check the simple stuff. Mine has thrown this code often since new. It can be, and I would say is often, set by poor quality DEF fluid. If you have no other codes. I would first check for leaks, use the DEF pressurizing test on insite, then get under and look for leaks. Then replace the DEF pump filter if it has been in longer then 50K. Then unplug both NOX sensors and reseat them with a little di-electric grease. Then clear the code. If it comes back, which mine never has after the above, then pull and inspect the decomposition tube for deposits, and look into replacing the nox sensor or sensors.
4364 18 is such a BS code quickserve even says "do not replace parts because of it unless other codes are present"
If connected to insite during a regen and both sensors are reading stable, I would leave them be. When one goes bad it will usually throw its own code. I have replaced the in 3 times and the out twice in 600K.