Exhaust System Service Required

[jwskrintney]

While pulling my fifth wheel yesterday, I pulled out to pass a truck going 30 mph in a 65 mph speed zone. I had lots of room to make the maneuver so while I did accelerate harder than normal, I did not get on it really aggressively. The following alarm came in as soon as I did this. "Exhaust system service required see dealer". Unfortunately I was on a two lane road with no shoulders for another ~30 miles or so. As I continued driving the alarm continued to "re-ring" every couple of minutes. The truck power gradually started to decrease and eventually got to the point where I could not get above 40 mph. In addition the transmission eventually stopped down shifting and transmission temperature started to rise (normally runs 164...got up to 174). At that point, I was finally able to pull off into a truck stop. I allowed the truck to fast idle until the transmission temperature returned to normal, then shut the truck down for several minutes. After re-starting the truck, the alarm cleared and it seemed to operate normally for the last 20 miles or so of the trip. I am concerned about this recurring on the trip home. Anyone have any experience with this or insight on what might be going on?

 

[Diesel85]

Without codes, my hunch is it may be a fuel system issue.

When was the last time the fuel filters were changed?

 

[jwskrintney]

The fuel filters are @ 16,000 miles. Have new ones at the house but didn't have time to change them before this trip. Certainly 1,000 miles over should not cause this kind of issue. Most of my driving is unloaded highway.

 

[Diesel85]

The fuel filters are @ 16,000 miles. Have new ones at the house but didn't have time to change them before this trip. Certainly 1,000 miles over should not cause this kind of issue. Most of my driving is unloaded highway.

Unloaded driving doesn't matter. The way the system works is the unused fuel goes back to the tank on the return line circuit from the HPFP.

 

[jwskrintney]

Appreciate the response.

 

[AH64ID]

I would guess you had an exhaust pressure sensor give an incorrect abnormal reading, which made the ECM think you had a DPF fault. Starting the truck the reading was normal so the message cleared.

If it is a bad sensor the dealership likely won’t be able to do much until it’s a hard fail.

Nothing wrong with 174° on the trans. Do a little stop and go towing and you get warmer than that. 164° is only the normal temp when the torque converter is locked.

Get those fuel filters changed asap, would hate to see a potentially unrelated emissions fault blamed on lack of maintenance.

 

[jwskrintney]

Thanks John. A faulty sensor was my first thought also....at least until the transmission stopped downshifting. That was the part that puzzled me. Heading home in a couple of hours with fingers crossed....

 

[AH64ID]

Thanks John. A faulty sensor was my first thought also....at least until the transmission stopped downshifting. That was the part that puzzled me. Heading home in a couple of hours with fingers crossed....

Sounds like the truck went into limp mode, so that’s probably what limited the downshifting.

 

[Shiner]

Personally, fuel filters are NOT a place where I would try extending service intervals, EVER. Our fuel quality in USA is sporadic crapppola.

 

[bcbender]

If it is a bad sensor the dealership likely won’t be able to do much until it’s a hard fail.

Sadly that is exactly my experience with these issues.

When my truck was only 6 months old the MIL kept going on during a cross country trip with the family and the 5er. 3 times I stopped a dealers to get it check and they could not duplicate, reset the MI, updated SW, and said keep driving,.. finally in Billings MT, I had the hard fail, thankfully I was able to limp back to a RV park and get a spot for the night and not in the middle of WY!! I turned back and got it into the dealer the next day where the diagnosed a faulty EGR valve causing underboost that was causing the MIL and eventually forced limp mode (truck could not tow those hills at more than about 15mph....).

Safe travels, and don't let them tell you it'll take 3 weeks to check it out.. Every dealer we called said that initially and I rebuked with its a new truck and Im on 3000 mi from home, usually they would squeeze it in finnaly.

 

[Ozymandias]

The fault will be saved in the ECM, the dealer can read what happened when the Message was on. Just do not play around with a scanner yourself.

And also, a "see Dealer Message" doesn't mean stop at the side of the road an call a tow truck, it is just a low level information that something isn't performing perfectly but no immediate action ist required otherwise the message would be different.
So, everyone, don't panic if that message pops up.

 

[jwskrintney]

Thanks for all of the replies. Fortunately, the truck did make it home without incident. I immediately changed the fuel filters (as planned before beginning the trip). The rear filter had normal expected discoloration for a ~15,000 mile change. The front filter was almost as clean as the brand new one (also installed the new aluminum cap from Geno's on the front filter housing....hate the plastic factory one). Next step will be to get it to the dealer. I am not surprised to hear the comment from bcbender that the EGR valve was part of the problem. I had a similar issue on my 2012....but it had 70,000 miles on it at the time versus the 16,000 currently on my 2024. Thanks again to everyone. It is nice to know there is a forum and people who take the time to help out in situations like this!!

 

[Diesel85]

Thanks for all of the replies. Fortunately, the truck did make it home without incident. I immediately changed the fuel filters (as planned before beginning the trip). The rear filter had normal expected discoloration for a ~15,000 mile change. The front filter was almost as clean as the brand new one (also installed the new aluminum cap from Geno's on the front filter housing....hate the plastic factory one). Next step will be to get it to the dealer. I am not surprised to hear the comment from bcbender that the EGR valve was part of the problem. I had a similar issue on my 2012....but it had 70,000 miles on it at the time versus the 16,000 currently on my 2024. Thanks again to everyone. It is nice to know there is a forum and people who take the time to help out in situations like this!!

Glad you made it back home. That's the most important thing.