Egr valve

[Gill Oruga]

A bad EGR valve will almost always trigger a position code when they go bad. On these CM2350 engines it takes quite a bit to take them out compared to a CM870 or CM871.

It may be a partially plugged DOC trying to constantly regen. I've seen them completely shut down a truck due to severe DOC face plugging and no codes for it.

Go on INSITE and once you stablish a connection, go to:

Advanced ECM Data----Aftertreatment History

Now you'll see the last 10 or so regens, DPF pressure and AFM temperature.
You're looking for regen frequency and quality. Is the engine calling for a regen every 8-12 hours? Or is it normal like 45-60 hrs between them?
A somewhat normal max DPF pressure is ...


{part of post corrected by Rawze: ... an average of around 3.0 in-HG or so for a healthy system ... }

... but if you mostly see 5, 7, or 8+ in-HG your DPF is likely plugged and will need to be cleaned/replaced.

Your temperatures should look something like this for normal operation:
DOC ~500* DPF inlet ~1,050* DPF Outlet ~1,100*

You can also see how hot and how plugged up your DPF has gotten on the window below.


One thing you can also try is doing the aftertreatment "reset all" procedure { ... but NOT a DPF replacement procedure.. leave that option alone} ... and record a complete stationary regen. This will make the fuel doser inject normal amounts of fuel in case you had issues with exhaust leaks in the past and it had to compensate. We should be able to tell how fast the temps go up from the catalyst to see if the face is plugged. How the turbo actuation is working and whether the EGR valve is being forced open or not.

If you want to check it while the regen is going, monitor the EGR differential pressure sensor and if it goes over 0.560 in-HG or above, the EGR valve isn't sealing properly or the motor is getting weak, which usually throws a motor overheat code.

The "reset all" procedure is:
Advanced ECM Data-----Aftertreatment Maintenance----Reset Options----All

[4MiraclesT]

Well for a little over a year after i replaced the dpf with a new one it would only regen every 60hrs or so and even then the soot load was only around 20% but when all thos started it has been regening more and more but nothing seems fo be clogged just getting more soot or unburned fuel heading down the tail pipe it seems.

[4MiraclesT]

Sorry i dont know why it turned my image

[Gill Oruga]

Record the stationary regen and go from there. Make sure you record all parameters at one sample per second.

Also, FYI that engine qualifies for a new SCR catalyst regardless of mileage (Campaign C2036) They normally cover the sensors that are damaged when removing them as well.

If your turbo/turbo actuator go bad you qualify for a free replacement at less than 435k miles.
Or you've replaced your turbo or turbo actuator out of warranty and paid out of pocket, at less than 435k miles you qualify for a reinbursement. (TRP T2258)

It's just finding a good dealer that wants to do the work under warranty is the issue. Most of them will turn you away or tell you that no parts are available.

[4MiraclesT]

So record all sensors for the full regen or just a portion? Also my turbo and actuator were replaced 1.5 years ago with a cummins reman unit but it shows on quickserve that my turbo replacement is covered till 2027 i wasnt sure if my scr was a qualified one because i cant see the little dimples they say to look for in the tsb release notes

[4MiraclesT]

I was looking back thru the old maintenance records and the scr was replaced at 504k miles not sure of it was a cummins part or not

[Gill Oruga]

(01-01-2023 )4MiraclesT Wrote:  So record all sensors for the full regen or just a portion? Also my turbo and actuator were replaced 1.5 years ago with a cummins reman unit but it shows on quickserve that my turbo replacement is covered till 2027 i wasnt sure if my scr was a qualified one because i cant see the little dimples they say to look for in the tsb release notes

When you go to data monitor just double click all parameters and then hit record.

Perform the stationary regen on the ecm test tab and once it finishes the regen make sure you save the log in a place you remember to be able to attach it and email it.

[4MiraclesT]

ok I'll give that a shot tomorrow

[4MiraclesT]

So i was able to log a couple of things. I did the regen which did fine. I also have a couple of driving samples as well one driving with an empty trailer and another with a full load. I did notice while driving that the egr is still being commanded open even under full throttle conditions. But im sure there’s something im missing as well