Seneca 2018.5 DEF tank error codes

[Rustynuts]

Personally I would insist they replace the DEF header. FCCC told me if the lines were reversed then header damage has already started due to the heat breaking down the sensors.

[Rustynuts]

You can check for codes, from the main menu touch the “Faults” icon.

[JohnAZ]

Agree Brian, header could be cooked. I will ask for that to be replaced regardless.

I checked for faults, just idling. Of course DEF all cooled down and concentration understandably a little lower if it's SG. Found 3 faults and saved them. I read the 3 lines in the Exploring doc on the Fault page. I don't think these are related to DEF - maybe the Body controller could be related, but Unknown SPN and no documentation is a dead end. Never have had a Check light while owned. This area of the App probably needs some work...

Thanks for feedback!

[JohnAZ]

Intended to be attached to previous post.

[JohnAZ]

Finally made it in at Freightliner, coolant hoses to DEF tank were found swapped on our 18.5 Seneca. I didn't have BlueFire up or Scan gage until this fall so was unaware of the issue until reading this thread. Had no symptoms or breakdowns maybe because our travels were mostly spring and fall, and stayed planted in a cool spot except for short trips during the AZ heat. This "winter" I did a couple of test runs and it would go above 140F after about 20 miles, with ambient of 65 or so.

No charge on the repair, and the service order stated they disconnected the supply at the engine, and at the frame rail connector beside the DEF Tank. Attempted to blow air thru hose, nothing came out. Swapped hoses at the frame rail, added coolant, and pressure and leak tested. Good to go.

I watched DEF temperature on the way home, didn't budge. No alarms or codes, DEF had cooled down to 87F, so hopefully the case is closed for me.

Sincere thanks to all who contributed updates their situations. I am disappointed that Freightliner was so slow in communicating this issue. Corporate direction is to just swap hoses and not replace any other parts (header, sensors, etc.) unless there is a detectable (scan code?) failure.

[JohnAZ]

Originally Posted by JohnAZ

Intended to be attached to previous post.

Update, these "Faults" came with the Test Data that comes with Blue Fire, not my rig...

[Rustynuts]

Originally Posted by JohnAZ

I am disappointed that Freightliner was so slow in communicating this issue. Corporate direction is to just swap hoses and not replace any other parts (header, sensors, etc.) unless there is a detectable (scan code?) failure.

I am shocked that this was never even a TSB to take in to be checked, Freightliner probably could have saved a lot in towing costs. I’m surprised that they didn’t replace Header, early on they were replace even of the lines were found crossed. Mine did throw the code and they replaced mine.

[repeach]

Just read all 6 pages of this thread.
Our S2RV Seneca was built in Jan 2018. I had the MIL light come on 3 times within the first 2 years in hot weather. The last time they replaced the entire Header.
I have no idea if the lines are correct or not because I have only been in cool weather since. The header was replaced on 9-11-2019. I wonder if the Freightliner dealer knew about it and corrected them when he replaced the Header.
Also wondering, if they are backward wouldn't both lines become warm to the touch when the engine is running? If there is a check valve working correctly wouldn't one of them stay cool?

[miles ahead]

not sure, i do know that two freighliner dealers had no idea what i was talking about when i mentioned the hoses being attached wrong. i had the second shop call their nationwide service tech while i was listening. the tech explained in detail what needed to b replaced & to correctly identify the hoses.

[Gunfighter]

Originally Posted by rpietsch

Just read all 6 pages of this thread.
Our S2RV Seneca was built in Jan 2018. I had the MIL light come on 3 times within the first 2 years in hot weather. The last time they replaced the entire Header.
I have no idea if the lines are correct or not because I have only been in cool weather since. The header was replaced on 9-11-2019. I wonder if the Freightliner dealer knew about it and corrected them when he replaced the Header.
Also wondering, if they are backward wouldn't both lines become warm to the touch when the engine is running? If there is a check valve working correctly wouldn't one of them stay cool?

I cannot say one way or another, but if I were to guess I suspect your lines are reversed. I was told there is a thermostat on the lines and they should not try to "warm" the DEF unless its close to 32 degrees outside. Are you able to check yourself using the the routing diagram posted earlier in this thread?
I believe continuing to run with lines reversed burned out three valves and a DEF header on mine. Good luck.

[01 mixson]

Coulld you put that diagram on your post, thanks

[Rustynuts]

Originally Posted by 01 mixson

Coulld you put that diagram on your post, thanks

Here is a link to them. It can be very difficult to trace them where they turn Nd cross over from the passenger side to drivers side. Taking a marker and marking the line you are tracing about every 6” helps to keep things straight.

https://postimg.cc/gallery/Fzp3Rcg

[repeach]

Originally Posted by Rustynuts

Here is a link to them. It can be very difficult to trace them where they turn Nd cross over from the passenger side to drivers side. Taking a marker and marking the line you are tracing about every 6” helps to keep things straight.

https://postimg.cc/gallery/Fzp3Rcg

Those are the same pictures I just got form fccc via email.
As you stated, I lost the tracing between the frame rails. Do you have any idea where they mixed up and crossed the lines. On the top of my DEF tank it looks just like the pics.
I am wondering if they just hooked up the engine sides backwards.

[01 mixson]

Thanks a bunch i have a late 2020 37k i'll check it out

[Rustynuts]

Originally Posted by rpietsch

Those are the same pictures I just got form fccc via email.
As you stated, I lost the tracing between the frame rails. Do you have any idea where they mixed up and crossed the lines. On the top of my DEF tank it looks just like the pics.
I am wondering if they just hooked up the engine sides backwards.

They are usually hooked up backwards on the inside of the drivers frame rail at the frame bulkhead pass-thru fittings. They seem to get twisted and out of orientation where they are coming down the passenger frame rail, and turn 90° and head to drivers side, which is the hardest section to see. Some people have disconnected the hose on each end and then blown air through them to determine which hose is which. Like I mentioned, use a marker and start marking one line makes it much easier to keep track of, when you come to the 90° turn area and it passes through a cross member, try and shift the hose and mark to the other side. When I corrected it, I took the time to remove the hose out of every strap that held the hose in place and positioned the hose according to the drawings and fastened them back in place. Here are some pics of my marked hoses from front to back. As you can see, the hose coming down from the back of the head runs to the rear bulkhead fitting and it should be on the front one. This is after a Freightliner tech said that my lines were fine....come to find out he only traced the lines on the outside of the frame to the tank

[01 mixson]

Do you know if it was still a problem with the 2020 model year, ? my rig only has 2000 miles on it have not had any problems yet

[repeach]

In my emails with FCCC I asked about a TSB. Here is the reply:

No, there has not been issued, nor have I heard any plans for one in the future.

Regards,
John Michaels
Senior Service/Parts Administrator
FCCC Service
Daimler Trucks North America LLC
Phone 800-385-4357
fcccservice@daimler.com

[Rustynuts]

Originally Posted by 01 mixson

Do you know if it was still a problem with the 2020 model year, ? my rig only has 2000 miles on it have not had any problems yet

It shouldnt, but it is possible. I have read posts about 2020's that had them crossed.

[repeach]

Originally Posted by Rustynuts

They are usually hooked up backwards on the inside of the drivers frame rail at the frame bulkhead pass-thru fittings. They seem to get twisted and out of orientation where they are coming down the passenger frame rail, and turn 90° and head to drivers side, which is the hardest section to see. ...

Got them swapped. Fortunately I cemented my barn and I have a pretty good creeper. I chased out the lines fairly easily and they were twisted by the passenger frame rail. I switched them just inside the drivers frame rail.

Now I am hoping I get my Bluefire before we leave on Sunday so I can monitor the DEF temp :- )

BTW, I double checked the MFG date in the Drivers door. My coach must be one of the first of the 2018 S2RV chassis.... Manufactured in Sept 2017.


Thank you everyone for the help and your knowledge. As everyone says, there is so much "KNOW HOW" on this forum !!!!

[01 mixson]

Thanks i'll check it out