LZ0 P2463 - "Service Regeneration required" - I drove it for 30 miles and restarted 5 times and it stopped going into limp mode

DubVBenz · May 16

I have a 2024 Sierra 1500 LZ0 3.0 Duramax with less than 2K miles since purchasing new in January. Since new, I have had to replace two NOx sensors, one exhaust gasket and one melted DEF injector between two different dealer visits. I've been driving it normally without issues since the end of March, but mostly with very short trips (4 miles to work, 4 miles back, occasional longer trips). Today I filled up my tank in anticipation for a road trip I'll be taking this weekend with 50 cetane diesel, which is the only station I use because of the higher quality diesel. Shortly thereafter, the truck went into a limp mode with a CEL and a warning about reduced performance. I've owned old and modern diesels forever, so I assumed a clogged DPF. I had Onstar scan it and they returned the P2463. Because I absolutely need this truck for a 2K mile road trip I have been planning for months, I decided to see if I could burn off the soot. I drove it 30 miles and used the paddle shifters to ensure I was running high RPMs on the highway. I also restarted the truck several times at any point when I stopped, which eventually stopped the limp mode, but my CEL remains (I know they'll persist through several more drive cycles even if the issue has been resolved).

Based off research on the older V8 models, I see this guidance:

DTC P2463
When DTC P2463 sets, the ECM will no longer try to perform a driving regeneration and the vehicle will require the more controlled service regeneration. There are a number of factors that can cause the code to set, including:

- The driver ignoring the Continue Driving messages
- Leaks from intake or exhaust system
- Poor fueling in the engine
- Contaminated or bad fuel
- Externally damaged or worn components.
- Loose or improperly installed components
- Dirty components (air filter or TMAP sensor)
- Driving style, such as binary driving (frequently on/off accelerator or brake)

So my questions are:

1) What is a service regen? Is it something that can only be done via a scan tool, or can I simply blow out the DPF on a manual drive ?
2) Is this really a critical problem that only a dealer or mechanic can resolve? I have a family member with a Euro shop that has all the good (not just euro ) scan tools and I can reset this myself
3) I absolutely need this truck for my road trip that has been planned for months, are there any critical reasons one can think of that I should avoid taking it?

My hope is I just needed a more aggressive drive cycle and regen, but I wanted to check with those more experienced with these engines before I go on my trip.

silveradosid · May 16

have your family member hook up the scanner and do a forced regen

KARNUT · May 16

I know lots of people who use diesels for work. The newer diesels with modern emissions need to be driven and worked. Business owners I know who used to drive only diesels including the wives. Now only use diesels for extreme duty and distance driving. All because of regeneration.

DubVBenz · May 17

14 hours ago, silveradosid said:

have your family member hook up the scanner and do a forced regen

I ended up using an Autel today to do a force regen cycle, but I should have read the values first because I had managed to manually regen it last night with the long drive cycle. Currently the sensors are reporting it as clean as a whistle. Some stats: 1950 Miles, 15 full completed regens, 208KM average interval between regens. I also cleared the code.

newdude · May 17

On 5/15/2024 at 8:58 PM, DubVBenz said:

I have a 2024 Sierra 1500 LZ0 3.0 Duramax with less than 2K miles since purchasing new in January. Since new, I have had to replace two NOx sensors, one exhaust gasket and one melted DEF injector between two different dealer visits. I've been driving it normally without issues since the end of March, but mostly with very short trips (4 miles to work, 4 miles back, occasional longer trips). Today I filled up my tank in anticipation for a road trip I'll be taking this weekend with 50 cetane diesel, which is the only station I use because of the higher quality diesel. Shortly thereafter, the truck went into a limp mode with a CEL and a warning about reduced performance. I've owned old and modern diesels forever, so I assumed a clogged DPF. I had Onstar scan it and they returned the P2463. Because I absolutely need this truck for a 2K mile road trip I have been planning for months, I decided to see if I could burn off the soot. I drove it 30 miles and used the paddle shifters to ensure I was running high RPMs on the highway. I also restarted the truck several times at any point when I stopped, which eventually stopped the limp mode, but my CEL remains (I know they'll persist through several more drive cycles even if the issue has been resolved).

2 hours ago, DubVBenz said:

I ended up using an Autel today to do a force regen cycle, but I should have read the values first because I had managed to manually regen it last night with the long drive cycle. Currently the sensors are reporting it as clean as a whistle. Some stats: 1950 Miles, 15 full completed regens, 208KM average interval between regens. I also cleared the code.

Worth a read: MC-10233833-0001.pdf (nhtsa.gov)

Assuming nothing is faulty (DPF is ok and not bad), this right here is a strong possible culprit as to why you ran into this code:

Quote

but mostly with very short trips (4 miles to work, 4 miles back, occasional longer trips).

2,000mi on a modern diesel over 5 months, and 208km or 129 miles between regens. That regen frequency is not great. These engines need a good proper heat cycling. They need to be driven more. 8 mile round trip to work is 2.7 Turbomax or 5.3 or commuter car or EV duty. Gas engines don't like short trips either but they can take it for longer without frequent issues.

The last bits from that bulletin are rather key too:

Ignoring the message and continuing to drive with the warning message ON and the exhaust filter not being cleaned as required will eventually result in the following:

7.1. The malfunction indicator lamp (MIL) will illuminate at which point the DPF warning message will be displayed and a chime will also sound.

7.2. Diagnostic Trouble Code DTC P2463 will be set as a result of excessive soot loading in the DPF.

7.3. The Engine Power Is Reduced message will be displayed. The engine WILL operate in reduced engine power when this occurs.

7.4. Once this occurs, self cleaning of the DPF is no longer possible and dealer service will be necessary.

7.5. Possible irreversible damage to the DPF may occur, requiring repair or replacement

Just some food for thought. I'm not suggesting to drop everything and trade it in, but I'm saying that it should at least have a nice 30+mi highway loop trip maybe once or twice a week to keep the emissions bits happy.

Edited May 17 by newdude

DubVBenz · May 17

Thank you for the detailed reply. Yes, I knew my short trips are the culprit. I have a 2007 Mercedes with a DPF that allowed the same sort of behavior for the first ~130k miles before it ultimately clogged and I did a delete. However, on that one, it did regens and worked just fine right up until then. Owing to my familiarity with a family member's european shop, the DPF service life may have been reduced a bit on mine, but they all generally go somewhere between 125-175 and need to have an extensive clean or replacement. IHowever, in terms of day-to-day, t would always just keep attempting until it was successful (you could tell by the smell).

I was hopeful that 12+ years of development may have ensured things had improved since then, but it sounds like they're even more restrictive now.

When I bought the truck I had intended to use it mostly for hauling/towing, but have ended up enjoying it so much all of my other cars have remained mostly parked since I picked it up.

One of my gripes (well, I have lots of gripes with all of the exhaust after treatments that cause such reliability problems in modern diesels) is that there's no real indicator that a Regen is approaching or in-progress. I guess I'll end up buying an banks gauge to give me that feedback so I know to keep driving when it's in-progress.

To the point 7.4

10 hours ago, newdude said:

Once this occurs, self cleaning of the DPF is no longer possible and dealer service will be necessary.

I'm pretty sure I had it complete a full regen by restarting it a few times at lights and then driving an additional 25+ miles that evening. I say that because while the CEL remained, full power was restored. Like I said, I should have checked the Live data on Autel before going ahead and initiating the service regen, because I suspect it was already clean. The service regen increased the RPM to around 2500 to get the exhaust gasses up to 300C. It ran like that for about 15 minutes but kept displaying "Conditions not met". I walked away and when I came back it was complete. My assumption for the "conditions not met" is that it did not have the appropriate level of soot to initiate a burn at that time. Live values after the fact showed it at 0%.

It's great that I have access to a scantool (which is 3500+1200 annual maintenance for new vehicle support), but not having the ability to resolve such a condition without a dealer (hopefully warranty ) visit or indy. The average consumer won't have access to those.

When I was searching for the code, I found plenty of 6.6s have had it, dating back to the first dpf models to even the newest ones. I bring that up, because often times the HDs are work trucks that sit idling for hours at a time at a job-site or driving at low speeds between one job-site to another. Those are going to have the same problems as the 3.0 as well.

I did read that there had been a software update a year ago or so for early LZ0s and maybe other GM diesels to address this. As per the dealer on my last visit, I have all the latest software. I'm not sure exactly how that was intended to address the issue.

newdude · May 18

11 hours ago, DubVBenz said:

I was hopeful that 12+ years of development may have ensured things had improved since then, but it sounds like they're even more restrictive now.

Oh without a doubt. The standards in 2007 when DPFs went main stream in 3/4 and 1 tons are weak compared to the 2010 standards and the current ones.

But light duty (under 8500 GVWR) are scrutinized a bit harder, especially after Dieselgate, than the bigger stuff (over 8500 GVWR).

DubVBenz · May 20

I should mention that after I resolved my issue, I did a 300 mile road trip through the mountains with the cruise set to 84MPH and the truck performed flawlessly. I'll be doing the return with a few hundred pounds in the bed in coming days.