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AndyShane

Freightliner XC Low Def Warning

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It seems that this warning can also be a harbinger of an impending LOW COOLANT annunciation.

We got the LOW DEF warning as the first indication of a leaking heater hose union, in a new 2019 Freightliner XC Class A.

'Turns out, Freightliner ships to the coach builders with heater hoses capped. Newmar, Tiffin, et al then remove the caps and link their dashboard heater cores via more hose.

In the case of my Newmar, a brass union was shoved into the hose-ends and a small worm-drive hose clamp was installed on each side of the union. In tightening the forward clamp, the wall of the hose was cut, a leak developed. It took nearly 8,000 miles to work its way up to a noticeable rate, the enclosure into which the hose was laid caused fluid to drip at the engine compartment and at the front of the coach.

Owners are cautioned to find where this union is, monitor the location for leakage. I've now owned three RVs, and two have developed leaks at this location.

Indication when ANTIFREEZE is low.jpg

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Interesting!

So a "low coolant" warning is displayed as a "!" above the  "low DEF" label?

SO,  is that the display for all warnings and the LOW DEF is just one of the monitored functions and perhaps a better label than "low DEF" could be used.

Does the display give any information other than "!"?

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Andy!  Think the coach builders Do not, or did not receive a torque level for the hose clamp(s)? 

The fact the builders are adding a section of hose, Are they using a lower quality hose or one that can be easily cut into as the heat increases in the hose and the material becomes softer ?

Or they need to use a wider hose clamp to spread out the clamp pressure over a wider area? 

IE reducing hose quality or smaller clamps, saves a few cents; but creates an issue that cost them more to repair under the warranty period. 

Rich.

 

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Correct me if I am wrong. Isn't that a DEF gauge just below the speedometer that reads full on the graph or is it a Soot level indicator within the Particulate filter? 

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Joe, I think that's the Soot level, looks like the warning for regeneration is on the lower left side off RPM gauge.  I see 2 yellow engine lights also on RPM gauge!

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9 hours ago, manholt said:

Joe, I think that's the Soot level, looks like the warning for regeneration is on the lower left side off RPM gauge.  I see 2 yellow engine lights also on RPM gauge!

If that's the case he doesn't have a DEF tank gauge :blink:. It looks to me like it needs DEF added and a parked regen performed. When DEF drops below a certain level the system will not function, which will cause the soot levels to climb rapidly. If the soot level is at 101% no passive regen (while driving) is going to knock that down enough. Typically at 95% blockage there is damage occurring to the turbocharger from the exhaust having no way to exit and coming back up to the turbocharger. 

I have a 2017 ISL in the shop now, driver ignored the parked regen request for a few days, took out the turbocharger and broke the Catalyst (DOC) causing it to move in the housing, it moved so far it hit the temp sensor, the DPF is so clogged it cannot be cleaned and there was so much heat coming back into the intake it wiped out the fuel injectors, those are scored internally from heat. $19,000 in damage all for ignoring the engine's request for a parked regen. 

The photo below, that should be flush with the end of the metal case, it got so hot it melted the glue.

Damaged DOC.jpg

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Joe, there was no level indicator on my Allegro Bus...I just looked in bay each time I filled up fuel and made note of level, at half mark I filled it up!  I only had structural (house) problems in the 57,000+/- miles I had coach! Powerglide chassis.

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Andy --

On my Freightliner dash display, my DEF tank level indicator has the same symbol as the DEF level gage on your display i.e. "blowing exhaust cloud with waves underneath".   My DEF level gage only shows horizontal green bars for 25%, 50%, 75% and 100% full levels (not the solid 0-100% bar like yours).   My dashboard DEF tank level indicator reading is generally consistent with the level gage on the DEF tank. 

Receiving a "Low DEF" warning message while your DEF Tank Level indicator show 100% full means a miscommunication in the electronics somewhere.   A "Low DEF Warning" would have nothing to do with a coolant leak.  I wonder if somehow the low level indicator in your coolant tank was incorrectly connected to the "Low DEF" warning "light" on your dash display?

Alternatively, this short dissertation says that a yellow "DEF Low" warning light can also indicate that the DEF tank was erroneously filled with something other than DEF --> https://www.yourmechanic.com/article/is-it-safe-to-drive-with-the-def-light-on

Also, the temperature indication in your photo is the engine temperature given the  "icon" (i.e. thermometer in fluid "boat" icon) above the numerical the temperature reading.  Correct?

Let the forum know how your "DEF Low" warning message was resolved.

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