How often does my 3L regen

ian cloutier · March 7, 2020

Picked up a 3L GMC Sierra last week and noticed after a short trip with 400kms on the truck it smelled like burning crap when we got home, I wonder if that’s a passive regen?

i was reading, does this truck passively regen every time it gets hot? Does it even need to active regen?

i found this online

”

There's no DPF (Diesel Particulate Filter) on the exhaust under the truck.

Unlike its big brother, the 3.0L Duramax doesn't have a traditional DPF. The clean-sheet design allowed the engineers to combine the SCR (Selective Catalytic Reduction) and DPF into one unit, which Barta's group refers to as the "SCRF."

"The SCRF is coupled close enough to the turbo that we actually do the regen post- injections on the exhaust stroke, and that extra fuel flows out the exhaust valve and straight into the SCRF," said Barta. This design makes the "passive regens" automatic and seamlessly unobtrusive to the driver.”

https://www.fourwheeler.com/news/features/1908-first-look-tech-details-behind-2020-silverados-new-3-0l-duramax-6-turbodiesel/

redwngr · March 8, 2020

Duramax regens are triggered based on any of dpf differential pressure (soot load), engine hours, fuel burned, miles driven. (there may be others)

There is not give an indicator that regen is in process.

Unusual smell is common for the first regen or first few regens is common.

Regen's will be about once per tank, but of course that depends on vehicle usage.

The continue driving message in the OM will only happen if it is unable to reduce the soot load after multiple attempts.

There is a blurb about all this in the Diesel Particulate Filter section of the 3.0 Duramax Diesel Supplement to the owners manual.

(it can be downloaded if you were shortchanged by the dealer OR prefer to also have a pdf copy)

6sigma · March 15, 2020

Mine seems to regen about once every 10 hours of engine time. Engine time seems to be more accurate estimate of when it might regen than miles, since it depends on how it is driven. I wonder if driven a lot at highway speeds or under load towing that it might get hot enough to do some passive regen? Also I wonder if cold starts produce a lot of soot that might cause the filter to fill sooner.

ILSilverado · March 18, 2020

About once every 500 miles. I have 3500 miles on mine and still getting that bad smell in the cabin. It’s at the Dealer for this right now. Mine used 2.5 gallons of DEF fluid in 3500 miles.

Kkajvr6 · April 6, 2020

I’ve seen about 2 regen per tank of fuel with normal driving.

newdude · April 6, 2020

Average should be once per fuel stop. Typically in terms of mileage, every 300-500 miles.

Texas3.0 · September 23, 2020

On 3/18/2020 at 3:10 AM, ILSilverado said:

About once every 500 miles. I have 3500 miles on mine and still getting that bad smell in the cabin. It’s at the Dealer for this right now. Mine used 2.5 gallons of DEF fluid in 3500 miles.

Mine is using 5 gallons of DEF about every 2200 miles.

Grover67 · September 24, 2020

1 hour ago, Texas3.0 said:

Mine is using 5 gallons of DEF about every 2200 miles.

WOW what type of driving are you doing or towing?

Mine don't use much at all even after the update.

-Grover67

Ojustracing · September 24, 2020

I just did 4300 miles/250 miles a day over the past month. Regens happen on my truck aprox 245 miles. Aprox 3 times a tank during this time. Anywhere from 180 miles to 303 miles. Towing I can get 500 miles. I use the torque pro app to monitor. It only has regens when soot level reach''s 100%. Fuel mileage over that distance was 35.4 mpg best tank was 36.7.

Texas3.0 · September 24, 2020

1 hour ago, Grover67 said:

WOW what type of driving are you doing or towing?

Mine don't use much at all even after the update.

-Grover67

I’m doing strictly highway driving. I took it in a few months ago because I felt it was using too much and I was told that it was normal consumption most likely due to high humidity and stricter emissions for 2020. Last week I had it back in the shop for a CEL and a ticking sound both of which went away by time I got it to the dealer. While it was there they said they did an update for excessive def consumption. I took it on a 600 mile round trip over the weekend and the digital gauge went from full to half a tank.

Ojustracing · September 24, 2020

5 minutes ago, Texas3.0 said:

I’m doing strictly highway driving. I took it in a few months ago because I felt it was using too much and I was told that it was normal consumption most likely due to high humidity and stricter emissions for 2020. Last week I had it back in the shop for a CEL and a ticking sound both of which went away by time I got it to the dealer. While it was there they said they did an update for excessive def consumption. I took it on a 600 mile round trip over the weekend and the digital gauge went from full to half a tank.

What does paperwork say in regards to the update they say they did for the excessive DEF consumption. Haven't seen anything about update for that

DemonWorks · September 29, 2020

Mine did it's first one just after 400 miles.

Upstate NY · September 29, 2020

Mine had a major problem during Regen. I've gone around 1,350 miles or so. Around 1,000 miles, check engine and DEF warning light came on. Info center told me to service the DEF system or it would go to reduced power. Drove it home, other half cleared the codes for me cause it happened on a Saturday and could not get to dealer. Drive fine until Thursday, 1,250 miles, same lights came on and motor cut out and shut off. Couldn't get it to restart. Waited 1/2 hour and it restarted. Drove 20ish miles, same thing...shut down and on the side of the road. Then it did it every 10 miles until I got within range of the dealership to send their wrecker. Dealership saying it's a crank shaft position sensor... I doubt that's the issue, but they're doing what GM is telling them to do. DEF is still on full... I hate having problems with a truck I haven't even made the first payment on. Twice more, I'm sending it back for lemon law and ordering a 6.2L. Never had trouble with my 2018.

Edited September 29, 2020 by Upstate NY
Forgot to add DEF comment

Brandonb0013 · December 10, 2020

On 9/23/2020 at 8:32 PM, Ojustracing said:

I just did 4300 miles/250 miles a day over the past month. Regens happen on my truck aprox 245 miles. Aprox 3 times a tank during this time. Anywhere from 180 miles to 303 miles. Towing I can get 500 miles. I use the torque pro app to monitor. It only has regens when soot level reach''s 100%. Fuel mileage over that distance was 35.4 mpg best tank was 36.7.

I also have the torque app but I do not see a DPF percent option, I only see DPF differential pressure. Can you help me in finding this information in the app? Thank you much!