DEF light,check engine light on

[subvet-THOR]

Happy new year everyone.As stated in the title the lights came on while traveling from NY to central Florida.The camper ran fine ,we stopped south of Jacksonville for a quick stop and when I got back on 95 the lights came on.Got very nervous.Wlfe made multiple phone calls asking for advice,but being a friday afternoon before the holiday averyone was shut down till tuesday,even the 24/7 direct help line from Freightliner. 24-7 direct ????,What the heck.WE continued on our trip at highway speeds of 70 mph and stand stills and the truck ran fine for the remainding 150 or so mlles. Have been doing tons of research,driving myself crazy with worry.
I have read about Lines being crossed possibly,Ect.Truck has 20,000 miles with no previous problems.
Any help greatly Appreciated

 

[Grumpy]

Did you get DEF at a truck stop? Maybe it's bad..

 

[Robbbyr]

Is your rig a 2018.5 on the S2RV chassis? If it is and you have never had the DEF tank coolant hoses checked, there is a high likelihood you have the crossed lines and a damaged DEF header.

If you have an early-2018 on the M2 chassis crossed lines and fried DEF header are unlikely, but other issues with the system are certainly possible.

 

[subvet-THOR]

Put DEF in from jug

 

[subvet-THOR]

The truck is a 2018.5 s2rv with 20 thousand miles with no previous problems.

 

[Rustynuts]

Since you have a 2018.5 I would highly suspect that you may have reversed coolant lines, here is a link to the drawing that you can check yourself and the twist usually occurs at the point where the lines turn 90 degrees from the passenger side to the drivers side, which is the hardest part to see. I would be contacting FCCC 24/7 as soon as they are available and have it checked out and scanned.

https://postimg.cc/gallery/Fzp3Rcg

 

[subvet-THOR]

Thanks Rusty,will call tomorrow.I find it hard to believe after all these miles it screws up now.

 

[Russc25]

I assume you've filled the DEF tank as necessary? (and it's DEF not water or anything else)

Nobody's said "pull the code" yet? First thing you need to do is pull the code(s).

 

[Rustynuts]

Nobody's said "pull the code" yet? First thing you need to do is pull the code(s).

I suggested above to get it into Freightliner to have it scanned. The issue is it takes SAE J1939 protocol data port and not your average OBDII, so you have to have the correct scanner which is expensive. you can also use a Bluefire or Scangauge if you have then available.

 

[subvet-THOR]

Called the fccc help line,told me probably something simple,not crossed lines.Told to take it to freightliner.They are booked till mid to end of march.......

 

[Robbbyr]

Called the fccc help line,told me probably something simple,not crossed lines.Told to take it to freightliner.They are booked till mid to end of march.......

Does your dealer know you are NOT a diesel pusher? Did you mention your rig is on a S2RV chassis? They might not understand S2RV, you might want to say it's a M2, they will certainly know what that is.

My local Freightliner dealer is always scheduling weeks out for "motorhomes" since they assume pusher. But when I have needed their service and clarified it is a M2 I get in in a day or two.

 

[Rustynuts]

I’m surprised that FCCC didn’t help you get it in sooner, have you tried different dealer? Have you asked if you can bring it by and they can at least read any codes? I would definitely use the diagrams I posted and trace the coolant lines as the 2018.5 is the most prone year for this issue. If you have travel plans, then there is the option of building or buying a DEF Simulator so you won’t get stranded in case of a header failure.

 

[subvet-THOR]

Well,heres the deal.Got a local repair shop to come out and scan the MH. All codes read to a def header that needs replacement.Waiting for a price to repair.Called fccc again and asked why it failed with only 20k ,might as well talk to a rock wall,no help at all.
Thought I did the right thing buying a diesel motorhome,what a mistake that was.Hopefully they can get the def header and get me fixed so i can make the 12000 mlle trip back home and sell this POS !

 

[Rustynuts]

Did you or the mechanic trace the coolant lines? Mine failed at 18k and the reason was because of reversed coolant lines which overheats the def and slowly destroys the sensors. Do you know you’re in service date? Emissions warranty is 5 years and if the line re indeed reversed, they should do a goodwill repair. I would call FCCc again and ask for a supervisor.

 

[subvet-THOR]

Out of Warranty.Fccc says my truck was built in 2017,no issues with crossed lines according to them.So I asked why header failure in just 20k miles.Could not get an answer.Even if I could trace the lines and find they are crossed what good would it dut of warranty and is freightliner going to take my word for it?Are they going to pay my repair shop? You know what that answer is.There should have been a recall for this issue.

 

[subvet-THOR]

They are so busy and the only work on motor homes 2 days a week.Have to wait till end of march to be seen.They dont care if I'm stranded here...

 

[SloPoke-TC]

They are so busy and the only work on motor homes 2 days a week.Have to wait till end of march to be seen.They dont care if I'm stranded here...

Does your dealer know you are NOT a diesel pusher? Did you mention your rig is on a S2RV chassis? They might not understand S2RV, you might want to say it's a M2, they will certainly know what that is.

My local Freightliner dealer is always scheduling weeks out for "motorhomes" since they assume pusher. But when I have needed their service and clarified it is a M2 I get in in a day or two.

Your post about "2 days a week" is the typical response that Freightliner Service will give a DieselPusher (Class A with the power-train in the rear of the motorhome) because they SUCK to work on.

Read Robbbyr's post again and call the Service manager and tell them you are on a M2 chassis where all they need to do is pop the hood like any other truck... You can get an "Express Assessment"(A Freightliner Service Term) by driving up and walking into the Service Department.

Next- Follow Rusty's post and trace back your DEF heater hoses, If you don't - they will just put another DEF header on backwards and you will be back in this situation a year or two down the road.

 

[Rustynuts]

Out of Warranty.Fccc says my truck was built in 2017,no issues with crossed lines according to them.So I asked why header failure in just 20k miles.Could not get an answer.Even if I could trace the lines and find they are crossed what good would it dut of warranty and is freightliner going to take my word for it?Are they going to pay my repair shop? You know what that answer is.There should have been a recall for this issue.

The warranty does NOT go off of the chassis build date but the “In Service” date that is linked to your chassis VIN number, the on service date is the day it is sold to the completed coach owner. My chassis is also a 2017 build date but my in service date is March 2018. They are lying when they say there are no issues with crossed lines, I have attach a Freightliner bulletin stating that there are issue and also states if out of warranty that they may “goodwill” and cover the repair. Again, your issue is most likely from crossed lines to have it fail like this.

 

[Jeepin Jason]

If you are out of warranty and will be paying for this all out of pocket, you might want to just order the header and do it yourself. You will avoid the markup on the part that the dealer will charge you plus overcharging you for the labor it takes to replace. This is a 1-2 hour job max. It is really not that hard of a replacement. However, as stated a few times already, you should get under there and trace the lines because headers don't normally just go out. These have been going out from the lines being crossed...

 

[Randyeng]

I have a 2018.5 37FS. Same thing happened to me in 2022 traveling from Colorado to Oklahoma for a race. Drove it another 1000 miles before i took it into a Transwest Freightliner shop. They ran the codes and determined in was the DEF sensor. Was not crossed lines. Had 12000 miles on the unit. Left it with them for 2 months waiting on a the sensor part. From advice from this forum, I called FCCC on a Friday and told them the situation.
In warranty, FCCC had a complete new DEF tank and sensor shipped to Transwest, and the RV was out by the following Wednesday.
Depending on the codes, they can also do a DEF delete, until you get the parts or in for service.
I was somewhat worried about driving it too far because it can go into limp mode at any time, and leave you stranded on the side of the road.
All the best, and dont give up too early on the S2RV.