clongtine

I have run into this as well on mine. Just one of the myriad of electronic gremlins on the '24's

@Pryme It is in the corner LOL.

Still here, and issues do persist on my front with the possessed '24. I found that I need to flip my RV to travel disconnect to prevent the trailer from back feeding voltage to my truck since I have began this practice my trailer connection woes have ceased thankfully. The hard shifting does seem to persist but not as bad at this point. I have a little over 8000 miles on my truck now and have parked it in "TIME OUT" for the winter hoping the next time I fire it up it will have adjusted its attitude and behaves far better moving forward but I am not holding my breath on that one.

@Kerry Pulaski yes my HD is a Duramax I do not have an oil smell and do not have any oil leaks either. I know the DMAX is prone to a small amount of oil consumption under heavy load for long durations. But most of my oil loss was under no load at all just highway driving with no trailer. Very strange behavior as my first DMAX which was a '21 used no oil ever so somewhat disheartened on this front.

The gremlins are plaguing mine as well just had a case of the dead DRL blinker which mystically fixed itself on drive to dealer. Truck is also using around 1.5 quarts of oil in 6k miles not towing which my '21 used none. My brother in law has a '24 HD AT4 as well and his just went through a case of the blank screen and no turn signal function at all for a period, power cycle fixed. It does seem there is certainly something going on with the "new to HD" global B CAN architecture. My '21 Denali had zero issues with all the same options as my current Denali short of what the Ultimate now added over what was the Black Diamond edition. It almost seems like the CAN experiences some sort of interference which causes these sporadic electronic issues that manifest and then disappear with no trace. I am certainly not an engineer but do work with technology and this certainly seems like a possibility of what is causing these gremlins to appear and then with an ignition cycle they disappear. I am not at all impressed with the move to google/android for the infotainment system as the nav has let me down mean lock up or loading route or any other myriad of technical glitches a number of times. Which is strange as my wife drives a '22 Volvo which also uses a Google/Android based system and her car has had 0 issues ever with the infotainment or nav systems. Calls to On Star sometime can yield an update or temp fix to the issues but I have seen most do come back and then disappear again by the time you get in at dealer. Just not overly impressed with the technical quality of my almost $100k truck . I will likely by another but god I hope by the time I am ready for my next truck which will likely be '26 model year they have this all sorted out.

My dealer did tell me to push the OnStar button anytime the screen has issues as they can reset and push updates to the truck to resolve most glitches.

I had this recall completed on mine and can confirm the truck does idle smoother now. I have not looked at fuel economy to see if there was a change yet. The dealer did say the update process was a pain as they had to scan the barcode on each injector one by one to complete the ECM update.

My '24 Ultimate has been plagued by these gremlins as well. Have taken to the dealer they flash modules then it is good for a while then the gremlins reappear. Example this weekend driving and XM rebooted twice while driving as well as google maps full random reboots map disappears and everything just a scroll bar while driving not in bad coverage area either. Mine has also played the route no route game a few times where it will just lock up and not show your correct location anymore. Not overly impressed thus far my '21 had zero issues the entire time I owned it.

Just received this update as well on my GMC, from what it said it was an update to assist in further OTA updates. LOL priceless.

Well just got truck back from dealer and..... They claim SEL was due to not allowing truck to regen, to which I stated I hadn't even driven it prior to the Reduced acceleration message. And when I am driving it is for hours towing my camper not just bumming around town so not much faith their manual regen at shop will resolve the issues but fingers crossed it does. Their notes state took a number of forced regens to clear codes. Passengers side mirror and running board issues they attributed to BCM update that was loaded to truck. Harsh shifting they claim their was an update to the TCM and ECM that should correct the issue does seem to shift smoother at this point so we will see. Another odd comment was it takes 13K miles for the Allison to break in so I should expect strange behavior until I get to that point. Not sure I buy that comment as my '21 only had 13K on it when I traded and it shifted smooth as silk the entire time I owned it. Again not sure on this one but fingers crossed the updates resolve. The GPS, climate and all other screen related issues they claimed to be attributed to software bugs states there was a large number of updates to be run on screen which they did and they stated should no longer experience loss of signal etc. moving forward latest update has been stable. I questioned why updates didn't come OTA and they stated these won't you have to bring to dealer which in my mind defeats the purpose of OTA sooooo not sure I buy that either but time will tell if updates resolve. As for the trailer connection mess they of course pinned the issue on trailer and say truck checks out fine my trailer does have solar so I will try the travel disconnect that is mentioned in other posts and see if that solves this problem once and for all. So overall positive trip to dealer but only time will tell if their fixes do truly resolve the issues I had. More to come.

My truck will be going in this Friday for a laundry list of issues my comment to the dealer was I think it needs an exorcism LOL. Primary being the SEL stating reduced acceleration see dealer followed on restart by a continue driving vehicle cleaning exhaust to which I have driven at interstate speed for over an hour with no change. Next start says reduced acceleration followed by the cleaning exhaust message. No idea what made the gremlins extra angry to start this but that is just one of the many strange occurrences I have experienced since owning this truck. Prior truck was a '21 Sierra Denali HD Black Diamond edition which I drove for a little over two years without a single warranty concern. Below is the list of things I have experienced since owning my '24 for just over a month and 3k miles 1. Passengers side mirror will not retract once extended on occasion this has happened twice now, push the extend/retract button twice or three times then passenger mirror will figure it out. 2. Passengers side power running board will not extend when door is opened this has as well happened twice now, number of ignition cycles resolved this as it would not extend period no matter how much you opened or closed the doors front and back on that side. Very interesting to watch a shorter person try to hop up into this beast with no assistance from a running board or step they have to get a running start and jump LOL my wife is short. 3. Very harsh 1st to 2nd shift when towing my camper '21 shifted smooth as silk regardless of load on truck this one is harsh then will studder at points along the way through the gears causing the truck to feel like it is surging. 4. Searching for GPS message on Google maps that stayed on no matter what I did for over 3 hours on a trip rendering nav completely useless, only thing I did to resolve was boot screen into safe mode then take it out. 5. Auto climate control has not been anywhere near auto a number of times now interior temperature of truck is HOT and fan will not go above low speed regardless of temperature set and yes the auto light is lit on the button. Numerous ignition cycles got that back in order for the time being at least. 6. WiFi hotspot works when it wants had to call OnStar to enable this has occurred once now where it will just show circling orb for WiFi Name and Password only fix was call OnStar they then had to enable as nothing in the truck would allow enable or disable for that matter. 7. This I know has its own thread but the check trailer wiring nightmare, I have a '24 Brinkley Z3100 RV that has now had the entire trailer wiring to the brakes including brakes themselves replaced due to this plague. I do have a Curt LED adapter between the trailer plug and truck as it sounds like LED trailer lights and GM trucks are NOT friends in any way shape or form and this has helped for the most part in keeping the annoyance level at least bearable but it still does occur in fact when pulling my trailer into its storage unit yesterday I got the message, nothing the whole trip down to the unit but just as backing in it shows up. Have also had where brake gain cannot be adjusted using the plus/minus button on module can push the buttons all you want screen just shows gain it was set at will not increase or decrease no check wiring message at the time even indicating there may be an issue. Not trying to be overly critical of this truck but my confidence has definitely been lost haven't owned a vehicle in quite some time that has had this many issues. In fact last of note was a 2001 Pontiac Grand AM GT3. I have owned over 20 trucks over the past 22 years trading usually every year or two at the most primarily was a RAM guy until their design got stale with no updates since '09 really for them on the HD side short of the interior refresh in '15. Had one Ford in '17 F250 Lariat which was nice then back to RAM's until '21 when I bought my first GMC was totally impressed with the 10 speed and DMAX coming from the 6-speed Cummins combo in RAM, so decided to order my '24 in March of this year looking for the refreshed interior of the Ultimate that may have been my biggest mistake yet. I certainly hope a few module flashes can get the gremlins out but considering the issues are not consistent short of the SEL and shift harshness I feel this may be just the start of the run around game with the dealer to try and get things back to good. Just posting in case anyone else is seeing some of this with their '24 I will post updates after its trip to the "doctor/priest/dealer" on Friday.

I had a '21 Denali with the snow plow camper package and now have a '24 Denali Ultimate without and the ride is noticeably softer without just my two cents.

Here is a pic of my 2024 with our new 2024 Brinkley RV.

Received my 2024 Denali Ultimate on Wednesday this week!!!! Ordered 3/11 took delivery 6/14. Love the new truck very impressive thus far.

My truck has been produced and now shows on dealers site as in transit. We are finally starting to nudge closer to the finish line hope it comes soon.

Mine took a little over a month from acceptance to production, actually received the your truck is being built email from GMC yesterday morning. Hope to see my truck by mid June or sooner.

Order was accepted today received the friendly email from GMC showing order placed status now the real wait begins. Almost a month to the day between deposit at dealer and acceptance.

2024 2500 Denali Ultimate ordered 3/11/23 still awaiting allocation.