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2025 Cummins--Anyone notice that DEF gauge not reading correctly?

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MacksRam

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2025 Ram 2500 Cummins---Anyone notice that DEF gauge not reading correctly on their 2025?
One time the gauge will read 3/4 a tank---then couple hours later shows 5/8 a tank---then it will read the same for several days. I don't really want to carry it into stealership and they flash it and mess up something else...... (because I can make do with it as it is)
 
Quick follow up to this DEF gauge issue (in case anyone else is experiencing this issue)
I carried truck to Ram Dealer today--as I suspected, it is a known issue that Ram is working for a fix. They are to contact me once they have a fix.
But here is what I wanted to know:
IF there is DEF in the tank and the gauge reads empty, will truck go in limp mode? Dealer said "No, truck will continue to operator normal".
 
I haven't seen fluctuating readings in mine, what I have noticed is much lower usage vs my '22 when towing so thats been nice. Hopefully thats an easy fix for Ya and good that it's not a limp mode trigger.
 
Jmonty said:
I haven't seen fluctuating readings in mine, what I have noticed is much lower usage vs my '22 when towing so thats been nice. Hopefully thats an easy fix for Ya and good that it's not a limp mode trigger.
Click to expand...
Jmonty, Yes, good news! My previous Ram Cummins was a 2017--seems like this 2025 DEF usage is about the same or maybe a little less. But I only have 3200 miles on the 2025 at this point...
 
Seems she 25's are getting much better mileage, so as far as DEF "usage," I'd be looking at the DEF MPG and/or DEF per gallon of fuel for comparisons. Possible it's using the same amount, but you're getting better mileage.
 
Brutal_HO said:
Seems she 25's are getting much better mileage, so as far as DEF "usage," I'd be looking at the DEF MPG and/or DEF per gallon of fuel for comparisons. Possible it's using the same amount, but you're getting better mileage.
Click to expand...
Brutal_HO, good point.
I leave at the end of the week pulling our Travel Trailer from MS to Grand Canyon AZ--will probably be a 4500-mile round trip total---I will be checking the DEF per gallon of diesel usage---I should have some good statistics by the end of the trip....thanks
 
Mine fluctuates as you mention especially in that less than full to 3/4 full range. 1 day needle will be at 3/4 on Big Horn gauge. Day 2 it'll be at 7/8 full then few days later, drops down and back up again. Yes, very annoying.
 
Gunnysarg7156 said:
Mine fluctuates as you mention especially in that less than full to 3/4 full range. 1 day needle will be at 3/4 on Big Horn gauge. Day 2 it'll be at 7/8 full then few days later, drops down and back up again. Yes, very annoying.
Click to expand...
I get it.... maybe Ram will come out with a "fix" soon... In the meantime, I am being sure to keep DEF tank full (or near full) regardless of what gauge shows....
If you happen to carry yours to the dealer let us know what they tell you. Thanks
 
agree, never get below 3/4 tank...just in case. Was there yesterday for p2281 CEL. Known issue with the 2025s and from talking to them, software update is coming for the p2281. Never even thought of asking until I saw Mack's post this morning.
 
MacksRam said:
Brutal_HO, good point.
I leave at the end of the week pulling our Travel Trailer from MS to Grand Canyon AZ--will probably be a 4500-mile round trip total---I will be checking the DEF per gallon of diesel usage---I should have some good statistics by the end of the trip....thanks
Click to expand...

Just watching comments on this forum and another, my "budget estimate" that I am using for what the cost of operation will be is ~ 1 gallon of DEF per 25 gallons of diesel. So for a 30 gallon tank, 1 gallon of DEF each fill up. Very rough estimate.
 
I will concur with HarryN estimate. Just topped my def off. That's 7.5 gallons of def since new and currently have 2543 miles. Roughly 339 miles per 1 gallon def. 1 passive regen and 1 active regen mixed in at the 2543 miles.
 
Just bought a 2025 Ram 2500 Tradesman and have really been impressed. I previously owned 4 Super Duties. My gauge in the cluster seems to read differently based on the angle the truck is driven or parked. I just filled the DEF tank and the gauge reads full. When I scroll through the menu in the small center screen in the center of the gauges and arrive at the digital DEF gauge, it reads empty. Anyone experience that or heard of that happening?
 
Racerxray1 said:
Just bought a 2025 Ram 2500 Tradesman and have really been impressed. I previously owned 4 Super Duties. My gauge in the cluster seems to read differently based on the angle the truck is driven or parked. I just filled the DEF tank and the gauge reads full. When I scroll through the menu in the small center screen in the center of the gauges and arrive at the digital DEF gauge, it reads empty. Anyone experience that or heard of that happening?
Click to expand...

Are you confusing the digital DPF gauge? It reading 0 is good.
 
Yes, analog gauges does fluctuate on my 2025 big horn. Some days, it'll show 3/4 full, next day maybe 7/8 full and anywhere in between on diff days. The electronic cluster gauge, if toggling through the screen is your DPF, not DEF. If zero, then it's clean. Mine will go as high as 30% then active regen was done to bring back to zero. You'll also have a passive regen that's not as noticeable as the active regen.
 
After completing a 2-week 4,000-mile trip of pulling my 22 ft travel trailer-- Let me give an update on the "fluctuating" DEF gauge:
1. IF you keep the DEF tank full (meaning you add DEF fluid often--regardless of what gauge shows) --it will usually show/fluctuate between 7/8 and Full.
2. We took the truck off-road on a 2-mile rough, rocky trial in Monument Valley AZ--it was "shaking/rocking" the truck back and forth----2 different times the gauge went to E and the instrument panel flashed a message saying something along the line of "DEF low--200 miles until limp mode--5 mph".
After we got back on the smooth rode the gauge came back up to 7/8 tank. What does this tell us?
 
Gunnysarg7156 said:
Yes, analog gauges does fluctuate on my 2025 big horn. Some days, it'll show 3/4 full, next day maybe 7/8 full and anywhere in between on diff days. The electronic cluster gauge, if toggling through the screen is your DPF, not DEF. If zero, then it's clean. Mine will go as high as 30% then active regen was done to bring back to zero. You'll also have a passive regen that's not as noticeable as the active regen.
Click to expand...
Thanks….we can chalk this up to being a Ram newbie!!!
 
Another point to list as it concerns DEF usage:
(For the 4000-mile trip---I would say this consisted of 250 miles driving empty and 3750 miles pulling the 22 ft Travel trailer)
I used exactly 10 gallons of DEF fluid.
(4-- 2.5-gallon Blu DEF Platinum jugs)
 
MacksRam said:
Another point to list as it concerns DEF usage:
(For the 4000-mile trip---I would say this consisted of 250 miles driving empty and 3750 miles pulling the 22 ft Travel trailer)
I used exactly 10 gallons of DEF fluid.
(4-- 2.5-gallon Blu DEF Platinum jugs)
Click to expand...

Thanks - will be very interested when you post the rest of your fuel use info in the other thread to go along with this.
 
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