Thor Forums

[Davie200]

Yes it's a Cummins 6.7 340 it's at a Freightliner service center where they are also addressing steering problem. I drove it back to storage where light came on I checked the engine diagnostics there were two codes. SPN7854FMI4OC2, SPN7854FMI6OC1. I also figured that they idled the engine moving it around which I would of done. Highway regent in it to blow the soot out. Unfortunately I couldn't as the steering problem was still there so I took it back. Been there for over a week. They claim they were going to do a regen parked there after they changed the sensor. Don't know if that was done as they keep working on steering as test driving it. They are in touch with Freightliner trying to resolve issues. Right now there in process of shimming idler arm or something to that effect than a test drive. I will ask next time I talk to them if regen was done. I had a Cummins in my pickup that would soot up from idling to long and I would take it out and burn off the soot. But that was before DEF process that has become the norm. Thanks for the info. Maybe you can shed some light on this. I'll pass it on.

Originally Posted by simidrm

I think you mean the dpf soot sensor, I have a couple questions as this is what I do for a living.
1. What engine is it probably cummins.
2. Did you take it to a cummins dealer or back to rv center?
3. Did they do a parked or forced regen?

If they changed the soot sensor 3 times it is not the sensor itself and more likely a wiring issue.

If they didn't do a parked regen to clear the dpf of soot then all the sensor in the world wont fix it.

It would help a lot if you could give me the engine serial number and what the exact codes were sometimes the dash display will show codes with a spn### and fmi## numbers they are fault code indicators.

When doing a parked regen with a computer they can chart all the sensors in the exhaust system and tell exactly whats going on instead of just changing a sensor because that was the fault code.

Just because it had a fault code for soot sensor could just mean that the engine has another issue that is causing soot build up in the dpf, which mostly caused by a lot of low speed idling of the engine.