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Reductant No Flow Detected 22 3500

mbarber84

mbarber84

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Good morning everyone. I’ve been having a reoccurring/ intermittent issue with my new 2022 3500 HO. At around 3,500 miles my CEL illuminated while under normal driving conditions. The truck was running fine with no sign of an issue. I immediately took the truck to my dealer since I was in the area anyway. They scanned the truck and came up with a code (I forgot the number) that stated “Reductant low flow detected”. I spoke with the technician who crawled under my truck to check to make sure there wasn’t anything physically wrong with the emissions system. No sign of an issue externally. Their best guess was that an “air bubble” went through the dosing unit and caused the code. They suggested clearing the code and adding a little fresh DEF to the tank (I was at approximately 1/4 full) and driving the truck to see if the code would return. I drove the truck another 2,000 miles without an issue. Yesterday the CEL came back on. Again, no noticeable change in how the truck runs or drives. I checked my Ram app and the code caused an “alert” in the vehicle health section but it does not give the code. I have an appointment today after work to get the truck scanned again. I’m thinking it’s the same issue related to “Reductant no flow detected”. Anyone experiencing similar issues?
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Brutal_HO said:
IMHO, Low Flow would indicate a pump failure , pressure leak, or dosing unit clog/failure.
Click to expand...

I agree. I gave them a chance to “clear” it the first time, but this time they need to start checking things out. I feel like my DEF consumption has been all over the map. There has to be a hard part malfunction somewhere. I’ll find out more after 3pm today when they scan it


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Brutal_HO said:
IMHO, Low Flow would indicate a pump failure , pressure leak, or dosing unit clog/failure.
Click to expand...

If it is a mechanical failure it must be intermittent as it took 2,000 miles before the issue caused a CEL. If it was a complete failure you’d think the light would’ve come back on pretty rapidly after they cleared it the last time.


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Picked the truck up last night. They replaced the DEF injector with a brand new one. The tech said it passed all tests and the road test went well. Truck seems to be running fine since that time, and I’m noticeably using DEF again, can see a minuscule movement in the gauge which is good. The truck went into regeneration on the way home from the dealer, DPF gauge now showing zero percent. Things like this make you thankful for that factory warranty, and for keeping my business local. My dealer took excellent care of me both before and after the sale. That’s what counts!9BD08A07-3858-4380-9FAF-9894C199C1F5.jpeg
 
Just had the same code on mine.....1900 miles... we'll see what they are going to do....
 
mbarber84 said:
One would hope they’re rallying these up. Seems to be increasingly more common.


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gots me a new injector....surprisingly they had one in stock...i was only the second truck at this dealer for this to come up....lucky me....
 
IndyRamDRW said:
gots me a new injector....surprisingly they had one in stock...i was only the second truck at this dealer for this to come up....lucky me....
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Glad they got it replaced! I was surprised when they said they had one in stock when I talked to them, I guess that’s a common item for issues these days. My trucks been fine since


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I just had this code thrown today as well. 2022 with 1900 miles. Unfortunately, my code was mixed in with many others.
I was accelerating to get onto the freeway and the truck slammed/bucked noticeably, enough to jerk me forward. Dash cluster said “service fuel filter” and RPMs shot up and stayed around 2000-2500. Truck would get to speed and maintain but kept RPMs high. Made it to the dealer but the fuel filter code was not there. These are the codes that were present:
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Just kidding, I just looked again and my code says “reductant level too low” instead of low flow. My mistake, sorry to derail.

I had half a tank of DEF though so not sure why it threw that one, might have been because the ECM was on the fritz.


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leeparnell89 said:
Just kidding, I just looked again and my code says “reductant level too low” instead of low flow. My mistake, sorry to derail.

I had half a tank of DEF though so not sure why it threw that one, might have been because the ECM was on the fritz.


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Click to expand...
I agree with @Brutal_HO ....did you seat all the fuses?
 
leeparnell89 said:
Just kidding, I just looked again and my code says “reductant level too low” instead of low flow. My mistake, sorry to derail.

I had half a tank of DEF though so not sure why it threw that one, might have been because the ECM was on the fritz.


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Click to expand...
Mine said the same when the DEF was frozen im not sure if that could have been your issue where you are climate wise
 
So, I'd never heard the term 'reductant' before so I just looked it up - "a substance capable of bringing about the reduction of another substance as it itself is oxidized" aka DEF.
CAT machines have a DEF manifold or 'header' in the DEF tank that measures DEF level, urea concentration (it should be 32.5%) and temperature.
When one of those headers fail it will generally wreak havoc with the system, especially if its intermittently.
Kinda sounds like what might be going on here. Not sure if RAM uses an in tank manifold or not.
 
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