The Truck is Full of def

 

Yes, there have been problems with the DEF level system. Sensor, wiring connections stc.

Not trying to be an ass, but you confirmed level by trying to add some?

If you've added some, the addition does not always register immediately.


Filling the DEF tank seems to be one of those things that some dealer prep types overlook or intentionally don't do.
Like the fuel tank, factory only does a partial fill -- presumably because sometimes they sit for a long time before being sold.

 

Yes, it's happened to some people. Drive it back to the deler to fix, given it's a '24.

 

3rd issue in less than a month of ownership lol drive it back tell them to give me back my ford

 

yes I knew it had Def but it was putting a message up that will reduce speed I thought it was going to go into fail safe mode i will take it back to dealer on monday for the 3rd time inless than a month lol

 

Please let us know what they say.

 

Yes, this is a common issue. It's best to refill the DEF (Diesel Exhaust Fluid) as soon as possible to avoid speed limitations.

 

Took a trip this past weekend towing our 6,500 lb. travel trailer. During trip the warning of "DEF tank empty - Speed limited in 500 miles" appeared. Sensors are not accurate so I did not panick.

I stopped and filled with fuel as planned, and DEF, about 55 miles later. DEF tank took 4.1 gallons.
Fuel took 24 gallons.
The 5 gallon DEF tank was NOT empty.

That was my 4th fuel fill-up since topping off the DEF. That ratio of 1 gallon of DEF: 1 tank of Fuel usage has been consistent thru my 100,000 miles.

 

Could you add your vehicle particulars to your signature.
Thanks

 

I thought I did that.
Does not show up.
I know more about my truck than my computer.

 

LOL... It's there now !
Thanks

 

Bro. Same thing happened to me. With 4thousand km on it. Had it towed back to the dealership 500km. They said sensor. They changed it. I was towing a travel trailer. Went the next few months not towing anything then hauled my pontoon boat and same thing but different this time. Truck is at the shop week and a half now and no fix in sight. Truck has 10thousand km on it. Not impressed, and they have been talking to Chevy for a fix and they don’t even know how to fix it. Long story short, baby diesel not good.

 

Sorry for your trouble. Just for the record I have about 14K miles on mine and at least 10K is towing a 7Klb RV. This truck has been flawless.

 

An issue for your truck, for sure. But we hear very few problems with the 3.0.

 

Nothing wrong with the 'cheap stuff', as long as it is fresh.

 

Yea, on my last trip towing the camper this happened to me. I watch my DEF Guage like a hawk. On the way up, I lost only 1 bar. On the way home I lost another bar, but still relatively full. 10 miles away from home, the tank went from almost full to empty. I freaked out since I knew it was going to limit my speed soon.

Luckily made it home and bought a jug of DEF. Only to find out the tank was still practically full. I only used up a half gallon of def from the new box I just bought. Turned the truck back on and it showed full again. It was like a false alarm. I was mad because I bought the def from Autozone and they charge $20 instead of $8 at Walmart. Didn't even need any, smh. On the bright side, I only lost a half to 1 gallon of def after driving 5 hours with a heavy 30ft camper.

 

Yea, on my last trip towing the camper this happened to me. I watch my DEF Guage like a hawk. On the way up, I lost only 1 bar. On the way home I lost another bar, but still relatively full. 10 miles away from home, the tank went from almost full to empty. I freaked out since I knew it was going to limit my speed soon.

Luckily made it home and bought a jug of DEF. Only to find out the tank was still practically full. I only used up a half gallon of def from the new box I just bought. Turned the truck back on and it showed full again. It was like a false alarm. I was mad because I bought the def from Autozone and they charge $20 instead of $8 at Walmart. Didn't even need any, smh. On the bright side, I only lost a half to 1 gallon of def after driving 5 hours with a heavy 30ft camper.

Just for an FYI, the first message you will get is along the lines of "in 500 miles" speed will be reduced. So no need to let that own you while out and about.

 

Good to know. This is my first Diesel, so I definitely panicked. I appreciate the info. I definitely didnt see the mileage counting down. Just red indicators saying empty. Thank you guys for the heads up.

 

Keep in mind this is an EPA thing not a GM thing. The EPA is just tying the manufacturers hands on the error messages and what events are to follow. I see this falling soon into the gas market as well. We all know people who have had check engine lights on for years.

 

FYI. There has been a TSB out for a while regarding DEF usage. GM service bulletin 22-NA-150.

 

NA-150 is not really about usage it's about the DEF level being read incorrectly amongst other erratic DEF level issues. Along with the erratic level readings comes the low DEF pop up on the DIC and the soon to follow mileage countdown to limp mode BS.

 

Speed limit doesn't happen when it reaches empty.
Speed limit happens 500 miles after it reaches empty --- most will also need fuel before then....

This Techlink article gives the DEF Warning Strategy.
Also suggests that for some 20-21-22 vehicles, if def gauge is erratic that the info in 22-NA-150 may apply (software verification/update).

It was published end of Oct, 2024

Unable to Fill the DEF Tank – TechLink

gm-techlink.com

Unable to Fill the DEF Tank
October 31, 2024

The Diesel Exhaust Fluid (DEF) tank may appear to be empty shortly after beginning a towing trip or it may be difficult to properly fill the DEF tank on some 2020-2025 Silverado 1500, Silverado 2500HD/3500HD, Tahoe, Suburban, Sierra 1500, Sierra 2500HD/3500HD, Yukon; and 2021-2025 Escalade models equipped with a diesel engine (RPO LM2, LZ0, L5P). Under high load towing conditions, the amount of DEF used may engage the DEF warning system before the DEF system can read the tank has been filled. If the tank is filled under these conditions, the DEF system will not see the fill and may not see subsequent fill attempts. (Fig. 5)

Fig. 5

The vehicle should be driven to allow the DEF warning system to progress until a specific speed limitation warning is displayed on the Driver Information Center before adding DEF to the tank. In the U.S., the speed limitation will be 65 mph (105 km/h).

TIP: Refer to Bulletin #22-NA-150 to verify the Reductant Control Module is has the latest update available and that the Reductant Fluid Tank Level has been reset.
The DEF level also can be exacerbated by vehicle loading that exceeds the Gross Combined Weight Rating (GCWR) when towing. Reference the towing label inside the driver’s door and, using a commercial scale, confirm that the total weight of the vehicle, trailer and cargo does not exceed the GCWR.

DEF Warning Strategy
When the DEF warning strategy is implemented, it is based on an estimated range to speed limitation of 1,000 miles (1,609 km). When the gauge is reviewed during the warning strategy, the gauge will show very little DEF or no DEF at all. This is a normal condition. The DEF system needs to complete the warning strategy (Fig. 6) and inducement is not shown on the gauge. Only the reserve level is displayed in some cases. With large trailers, there may not be a reserve and there will not be any gauge bars displayed.

Fig. 6

Do not immediately add DEF when there is a DEF system message and a low gauge reading in order to drive the gauge back up or to remove the DIC message. The following chart (Fig. 7) shows the DIC messages that may appear while towing and the messages in red where it is not appropriate to add DEF to the tank. Areas in green indicate that at these warning levels and when these messages are displayed it is OK to add DEF to the tank.

Fig. 7

Customers should be encouraged to not fill the DEF tank under these conditions until the warning strategy indicates a specific speed limitation will be reached (65mph/105 km/h). When the system message changes from “Speed Limited Soon” to “Speed Limited to 65mph in xx Miles” it is safe to add DEF and the fill will be detected. The messages may stop for a short period, but they will begin again shortly if the vehicle is still towing. The vehicle can continue to be operated until the DIC message is displayed that inducement and speed reduction are imminent. This is technically the best time to fill the DEF tank, and the system will register a fill at the inducement level if DEF has not been added during the warning strategy and there are not any functional issues with the DEF system.

TIP: When adding DEF to an empty or very low tank, always add at least 2 gallons (7.2 L) of DEF to release the vehicle from speed limitation.

Check out Bulletin #24-NA-196 for more information.

 

Speed limit doesn't happen when it reaches empty.
Speed limit happens 500 miles after it reaches empty --- most will also need fuel before then....

This Techlink article gives the DEF Warning Strategy.
Also suggests that for some 20-21-22 vehicles, if def gauge is erratic that the info in 22-NA-150 may apply (software verification/update).

It was published end of Oct, 2024

Unable to Fill the DEF Tank – TechLink

gm-techlink.com

Unable to Fill the DEF Tank
October 31, 2024

The Diesel Exhaust Fluid (DEF) tank may appear to be empty shortly after beginning a towing trip or it may be difficult to properly fill the DEF tank on some 2020-2025 Silverado 1500, Silverado 2500HD/3500HD, Tahoe, Suburban, Sierra 1500, Sierra 2500HD/3500HD, Yukon; and 2021-2025 Escalade models equipped with a diesel engine (RPO LM2, LZ0, L5P). Under high load towing conditions, the amount of DEF used may engage the DEF warning system before the DEF system can read the tank has been filled. If the tank is filled under these conditions, the DEF system will not see the fill and may not see subsequent fill attempts. (Fig. 5)

Fig. 5

The vehicle should be driven to allow the DEF warning system to progress until a specific speed limitation warning is displayed on the Driver Information Center before adding DEF to the tank. In the U.S., the speed limitation will be 65 mph (105 km/h).

TIP: Refer to Bulletin #22-NA-150 to verify the Reductant Control Module is has the latest update available and that the Reductant Fluid Tank Level has been reset.
The DEF level also can be exacerbated by vehicle loading that exceeds the Gross Combined Weight Rating (GCWR) when towing. Reference the towing label inside the driver’s door and, using a commercial scale, confirm that the total weight of the vehicle, trailer and cargo does not exceed the GCWR.

DEF Warning Strategy
When the DEF warning strategy is implemented, it is based on an estimated range to speed limitation of 1,000 miles (1,609 km). When the gauge is reviewed during the warning strategy, the gauge will show very little DEF or no DEF at all. This is a normal condition. The DEF system needs to complete the warning strategy (Fig. 6) and inducement is not shown on the gauge. Only the reserve level is displayed in some cases. With large trailers, there may not be a reserve and there will not be any gauge bars displayed.

Fig. 6

Do not immediately add DEF when there is a DEF system message and a low gauge reading in order to drive the gauge back up or to remove the DIC message. The following chart (Fig. 7) shows the DIC messages that may appear while towing and the messages in red where it is not appropriate to add DEF to the tank. Areas in green indicate that at these warning levels and when these messages are displayed it is OK to add DEF to the tank.

Fig. 7

Customers should be encouraged to not fill the DEF tank under these conditions until the warning strategy indicates a specific speed limitation will be reached (65mph/105 km/h). When the system message changes from “Speed Limited Soon” to “Speed Limited to 65mph in xx Miles” it is safe to add DEF and the fill will be detected. The messages may stop for a short period, but they will begin again shortly if the vehicle is still towing. The vehicle can continue to be operated until the DIC message is displayed that inducement and speed reduction are imminent. This is technically the best time to fill the DEF tank, and the system will register a fill at the inducement level if DEF has not been added during the warning strategy and there are not any functional issues with the DEF system.

TIP: When adding DEF to an empty or very low tank, always add at least 2 gallons (7.2 L) of DEF to release the vehicle from speed limitation.

Check out Bulletin #24-NA-196 for more information.

My pitch to bitch is you can't dismiss the POP-up on the DIC when/if you've gotten to that level of it blocking the info screen. To me that's a BS kind of deal when you can't get to the info screens behind that pop-up. I will say applying that TSB does tame the time frame a bit. When towing mine would start the 1000 mile count down until empty with 7 out of 8 bars on the DEF gauge. My i-Dash would be at 92-93% DEF Level when the message would pop up. Now it's down to 60% or 5 out of 8 bars on the DIC DEF gauge. So at least it's not as annoying as it was before but I still wish it was more in the 40% range but I guess it is what it is at this point.

 

On a recent 800 mile trip with 12' u-haul trailer in tow, I got a "DEF mileage 978". I was going from TX to CO (final elevation 8000ft) in a 25mph headwind at 75mph. Gas mileage dropped to 12mpg (normally average 27 without towing). After a few more hours of driving I got a "DEF mileage 748". The odd thing was my DEF gauge was only 2 segments low ??? Before this, I was getting 4000+ miles on a full DEF tank. Now truck is telling me ~1000 miles left on 3/4 tank of DEF. Do I trust the gauge?

 

It's calculating the usage based on current fuel consumption. Once the trailer is removed and your average mileage goes back up it will recompute the distance to empty on the DEF tank the massage will go away.

The gauge itself is accurate so don't bother to try to add DEF because it will only end up running down the side of your truck if you're only 2 bars down from full.

The TSB took the warning from 1 to 2 bars from full to 4 bars from full before it starts throwing warnings at you. It's not a total fix but it's better then it was before the TSB was applied.

EDIT:
Oh and this is based on towing an 8K lb RV.