Check Engine Light

[Davie200]

Ok now what. Check engine light came on with two codes relating to the PDF. Brand new Thor Plazzo pusher 1800 miles on it. Took it to service and they said yep soot sensor bad. Changed. They had to test drive home for steering problems and light came back on. Hmmm. Well they changed the sensor again?? Ok. They are the pros. Worked on steering problem which needed a test drive. Yep. Check engine light came on again. They have no idea why now. Also steering is still bad. I really wish motorhomes has a lemon law clause cause I got one. It's going to cost me big ones to trade it off. But maybe more to keep it as it's not even three months old to me and the future looks bleak.

[99dart]

That's too bad. We have a friend here in town coming up on the 1 year mark on their 30.3 Ace. They haven't had it out for a trip yet. But, 4, 125 mile trips back to the dealer for numerous issues. He is just livid about the wasted year of use.

[Pete'sMH]

Originally Posted by 99dart

That's too bad. We have a friend here in town coming up on the 1 year mark on their 30.3 Ace. They haven't had it out for a trip yet. But, 4, 125 mile trips back to the dealer for numerous issues. He is just livid about the wasted year of use.

Find another dealer! These things are not starships. They can be fixed by qualified mechanics. Just have to find one. Don’t give up. Good luck

[16ACE27]

Originally Posted by Davie200

Ok now what. Check engine light came on with two codes relating to the PDF. Brand new Thor Plazzo pusher 1800 miles on it. Took it to service and they said yep soot sensor bad. Changed. They had to test drive home for steering problems and light came back on. Hmmm. Well they changed the sensor again?? Ok. They are the pros. Worked on steering problem which needed a test drive. Yep. Check engine light came on again. They have no idea why now. Also steering is still bad. I really wish motorhomes has a lemon law clause cause I got one. It's going to cost me big ones to trade it off. But maybe more to keep it as it's not even three months old to me and the future looks bleak.

In some states the vehicle part of the MH IS covered by the Lemon Laws. Florida is one.

[mountainsam]

First of all I wouldn't take it to an RV Dealer for engine work. Thats covered by the engine manufacturer. Secondly, a lot of us have had issues that kept our shiny new MHs off the streets and highways. Most problems have been worked out and resolved allowing many happy miles and smiles. Don't give up too soon. Good luck.

[simidrm]

Originally Posted by Davie200

Ok now what. Check engine light came on with two codes relating to the PDF. Brand new Thor Plazzo pusher 1800 miles on it. Took it to service and they said yep soot sensor bad. Changed. They had to test drive home for steering problems and light came back on. Hmmm. Well they changed the sensor again?? Ok. They are the pros. Worked on steering problem which needed a test drive. Yep. Check engine light came on again. They have no idea why now. Also steering is still bad. I really wish motorhomes has a lemon law clause cause I got one. It's going to cost me big ones to trade it off. But maybe more to keep it as it's not even three months old to me and the future looks bleak.

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.

[The Gritz Carlton]

You can do all the regens you wish but if the DEF fluid is bad from sitting too long (very common with vehicles sitting around a long time)...the light will continue to come on. Drain the DEF tank and refill with fresh juice.

[simidrm]

Originally Posted by The Gritz Carlton

You can do all the regens you wish but if the DEF fluid is bad from sitting too long (very common with vehicles sitting around a long time)...the light will continue to come on. Drain the DEF tank and refill with fresh juice.

Ya that's good advice but doesn't pertain to his problem he said dpf soot sensor which is only in the dpf system and def fluid is only used in the scr system to reduce nox levels.

There are 2 parts to the exhaust systems dpf and scr.
the dpf collects and hold soot in a doc filter until its full enough to trigger a regen passive or forced the soot is burned into ash and held in the dpf filter then exhaust flows out the dpf through a decomp tube where the def doser is located and def fluid is injected into the exhaust stream and carried into the scr system where is is turned into basically ammona and with the metals made up in the scr the nitrous oxide is reduced to epa acceptable levels normally 80% less then the inlet nox and a little water vapor and nitrogen exit the tail pipe.

[simidrm]

Originally Posted by simidrm

Ya that's good advice but doesn't pertain to his problem he said dpf soot sensor which is only in the dpf system and def fluid is only used in the scr system to reduce nox levels.

There are 2 parts to the exhaust systems dpf and scr.
the dpf collects and hold soot in a doc filter until its full enough to trigger a regen passive or forced the soot is burned into ash and held in the dpf filter then exhaust flows out the dpf through a decomp tube where the def doser is located and def fluid is injected into the exhaust stream and carried into the scr system where is is turned into basically ammona and with the metals made up in the scr the nitrous oxide is reduced to epa acceptable levels normally 80% less then the inlet nox and a little water vapor and nitrogen exit the tail pipe.

Also if it were a def issue he would have codes for low nox conversion and it would eventually derated the vehicle to 5mph

[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.

[simidrm]

Originally Posted by 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.

I have not had a chance to look up the fault codes yet, but if freightliner is involved they are a cummins dealer and should be able to get it fixed right.

I see these kinds of problems everyday it is what I do 5 days a week and I am a cat tech ( certified aftertreatment tech) on both cummins and Detroit engines, and trucks get towed in about 3-4 every week mostly from aftertreatment issue's and is very rare for it to be the owner or drivers fault unless they run out of def fluid or put something else in it besides def fluid or ignored a parked regen request, so being that it is a freightliner chassis 80% are from faulty wiring straight out of the factory like improper routing of wires to wires zip tied to tight and rub on the frame.

But in your case it could be a few things either a wiring issue,or even a plugged air filter will cause excessive soot, as will a stuck open egr valve, but since yours is brand new and they have changed the soot sensor 3 times my bet is a wiring issue.

spn means suspect parameter number
fmi means falure mode indicator

spn is basically the part that failed, and fmi is the fault mode I.E open circuit,low voltage, or not plausible my favorite and that means no matter what scenario you run that engine through you cannot achieve the reading its seeing.

good luck let me know how it goes.

[Davie200]

They changed a wiring harness and while out test driving light came on again with same code. They have regen twice. They are now trying to contact Cummins for help. This after changing sensors. Where would the short be?? Tech also uploaded updates which it was two behind. Still no help. I now have home taking it to dealer to fix windshield problem. Its hard getting someone out to fix and that's the day so I have to take it there. Up the road from there is a Cummins service center. I'm going up there to chat while repair is being done. If need be I'll stop with home to see what can be done. Its just a sad state of affairs all around. I'm leaving for the south friday and need home fixed.

Originally Posted by simidrm

I have not had a chance to look up the fault codes yet, but if freightliner is involved they are a cummins dealer and should be able to get it fixed right.

I see these kinds of problems everyday it is what I do 5 days a week and I am a cat tech ( certified aftertreatment tech) on both cummins and Detroit engines, and trucks get towed in about 3-4 every week mostly from aftertreatment issue's and is very rare for it to be the owner or drivers fault unless they run out of def fluid or put something else in it besides def fluid or ignored a parked regen request, so being that it is a freightliner chassis 80% are from faulty wiring straight out of the factory like improper routing of wires to wires zip tied to tight and rub on the frame.

But in your case it could be a few things either a wiring issue,or even a plugged air filter will cause excessive soot, as will a stuck open egr valve, but since yours is brand new and they have changed the soot sensor 3 times my bet is a wiring issue.

spn means suspect parameter number
fmi means falure mode indicator

spn is basically the part that failed, and fmi is the fault mode I.E open circuit,low voltage, or not plausible my favorite and that means no matter what scenario you run that engine through you cannot achieve the reading its seeing.

good luck let me know how it goes.

[simidrm]

The after treatment harness is in sections there is one the covers the dpf filter one covers the def doses and they plug into a main harness inside the right inside of the frame rail and run to left side to the def tank and pump then off to the after treatment control module (acm) could be shorted anywhere in between those points easy way to track down the short is follow the harness and look for any green corrosion on the harness loom especially when it rubs against anything or is kinked or has sharp bends

[Davie200]

They have changed those harnesses and check engine light still comes on. Both Cummins and Freightliner think it's the ecm might be causing a false read. So the plan is to change it out but the Level 2 person? Freightliner has been talking to needs to kick it up to Level 3 for permission?? So here I sit and wait for Cummins. Freightliner has told me he's going to get pro active so maybe I'll get back in the road soon. I was suppose to leave for Florida tomorrow.

Originally Posted by simidrm

The after treatment harness is in sections there is one the covers the dpf filter one covers the def doses and they plug into a main harness inside the right inside of the frame rail and run to left side to the def tank and pump then off to the after treatment control module (acm) could be shorted anywhere in between those points easy way to track down the short is follow the harness and look for any green corrosion on the harness loom especially when it rubs against anything or is kinked or has sharp bends