Transient

I'm assuming you went to halogen due to cost of replacing an LED tail light. Have you considered installing an LED bulb into the halogen tail light. Lasfit makes a fairly inexpensive LED bulb with a resistor in it that prevents hyperflash.

I doubt it's the parking brake. If you leave the parking brake on, shift into drive, then start driving away the parking brake will automatically disengage. You're in Canada, so I'm assuming snow. I wonder if this is an overly aggressive or malfunctioning e-locker? Maybe something happening in the transmission that shouldn't be happening. I'm reasonably confident this isn't a parking brake issue.

How is this not covered under the powertrain warranty, which iirc is 5 year/60,000 miles? Is the powertrain warranty the reason you're obtaining financial reimbursement?

Did you attempt to adjust air pressure? Could be a simple momentary loss of signal. Getting the pressure to change in the tire could force the sensor to send a signal to the computer. If that doesn't work then maybe the battery in the sensor died and the sensor needs to be replaced.

GMCustomerService is more interested in getting you into a dealership so you can spend your hard earned money for service at an inflated cost than independent shops (I'm not a mechanic, nor advocating for one). It's stay with the pull your battery technique. 10-15 minutes arms to work for most electrical gremlins. I had a similar issue the other day where the DIC said 4wd system disabled. Drove to my kid's school, picked them, and returned home with no issues. The next time I started the truck up everything was fine. I didn't pull the negative terminal in this incident. GM vehicles seem to have mischievous electrical feelings that tend to fix themselves.

Oh, this is a question and not a how-to. I was fooled by the lack of punctuation. Very disappointed.

Another 2020 TB LT here with squeaking rear brakes when cold and just starting out driving. After a little bit of use, they quiet right down. This info would be handy to have just in case....

Does it look like a 2021, or a 2023?

Not enough information for us to start the typical internet debauchery of speculation galore of the most incredulous manner that amounts to terradiddle. All joking aside, we need more info. What time of day?; which direction were you heading?; and what was the weather like? are all great examples of the info we need. Personally, I've had ACC fail in a rainstorm, but that was in a Honda CR-V. I've heard of others having ACC fail when the sun was setting and low in the sky because it messed with cameras. More info is needed. The dealership may end up saying something similar if they can't identify a problem.

Maybe something isn't fully plugged in? There's a module behind the glove box next to the right firewall. From underneath you can reach up and check to make sure all the plugs are pushed into the module. All the cables to the module plug in at the bottom so it's a fairly easy thing to check without tools. The other thing you could do is remove the radio screen and make sure everything is plugged in securely there, too. You'll need some plastic trim removal tools to remove the big plastic upside down U-shaped trim that is going around the radio screen. They're also another trim plate at the very bottom. Then there's 6 or 8 screws holding the display in. The "display" includes the radio, climate control, etc as 1 unit.

Something smells like total bovine excrement. I have over 40,000 miles on my 2020 and haven't had this issue. Mix of highway and city driving, so the brakes get used quite a bit. I'm not even at 50% on the front pads yet. I think the dealership just told you what they needed to in order to sell you instead of actually fixing the problem. Just caught my local stealership attempting the same thing with my wife with 3 alleged oil leaks on her 2017 Traverse hoping she'd pay 4-figures to have them fix the problem. 3 alleged oil leaks, yet not a single drop in the driveway where she parks. I looked over the car and didn't find an oil leak anywhere. They also couldn't provide pics as proof. I have stories I could share of bovine excrement from stealerships, and so do many other people. This is why I always recommend getting a 2nd opinion. My 2nd opinion often comes from a non-dealer affiliated shop.

Are you putting the transmission in Park? My driveway has an 8% slope, and I've never had this issue. I put my truck in Park and engage the parking brake every time. I've never had this issue. Biggest reason I ask if you put your truck in Park is due to your rear wheels moving in that video. In Park the rear wheels should be locked. This looks like your truck is in Neutral. The difference between you and me is i don't get snow where i live.

I recommend finding the fuse and checking on that. GM had problems with phones charging and blowing fuses about 10-20 years ago. The fuse was constantly failing. I worked in rental cars about 15-20 years ago with a large fleet of several thousand vehicles, mostly GM. This was a PITA to deal with.

Are you able to obtain electrical schematics? That might tell you something.

Businesses exist to make money. If they can save costs somewhere, they will. Just because you paid more doesn't mean they paid more

 Just kidding Not a stupid question at all. The only secondary battery I'm aware of on Chevy trucks is for OnStar. I did a parts search on a couple websites. The main battery and the OnStar battery are the only batteries I could come up with. With that said, I've pulled a handful of disabled Jeeps and Dodges off the road because of battery issues where the vehicle failed to communicate with the key fob remote and wouldn't start back up. I have not encountered anybody with a GM product with this issue, yet. Only battery issue I've seen with GM cars is when a military servicemember returns from a deployment and the battery is completely dead and needs replacing because they didn't disconnect it, or put it on a batter tender, prior to leaving. I think you have very little to worry about and will be good to go for the most part.

Bilstein

Tail lights are about $750 each for the Silverado led tail lights. I can't imagine them being $1750 more for the GMC. I'd question your dealers integrity on that one. Have you checked to make sure you're not low on blinker fluid, lol?

Looks like a warranty matter to me

Yes

Tyler, For some reason I'm having difficulty responding with a quote. Can you please stop playing mental gymnastics. I did not state, nor indicate, the Magnuson Moss Warranty Act gives total protection to the consumer. It does give the consumer protections from negligent producers. As i very clearly stated, GM would need to prove the pulsar device was the cause of the problem. Has such activity been taken? Based on the OP's statements, possibly not. Statements from the OP are going to be one-sided, and should be taken as such. However, that doesn't mean they aren't being fully honest. With that said, the pulsar may not be the cause of the problem, and may also not be used in a manner that would alter the vehicle. Should the warranty be voided for simply plugging in an OBD2 scanner, too? GM is definitely heading that way since they are opposing "right to work on your own vehicle" legislation. In the future I hope you take text at face value and not perform mental gymnastics to manipulate what is said for your miniscule benefit. Trying to tear people down does not lift yourself up.

Anything and everything is always possible. Please tell us more about the truck, such as engine, trans, etc

Tell us more about the truck, please. Engine, trans, etc

Google tells me P0700 is a transmission or transmission control module issue. P0607 results in an ECU/PCM/ECM programming issue. In my very limited experience it could've been an emerges gremlin that appeared for just a moment and went away just a quickly. The light was probably on for several engine start/stop cycles (5-10) and not seeing any new issues during that time resulted in the light going off. Computer may still have a record of the DTCs. Going back to the auto parts store to see if the code still come up may help in knowing this. Btw, whenever I have a CEL on any of my vehicles I immediately press the OnStar button and have them check for issues. If they find anything at that moment they can email you the results so you can provide documentation to your dealer service dept.

I have 39,000 on my 2020 Silverado. 6.2 with 10 speed. No issues that I've noticed. I use to live in Highland Park (2012-2015). I had Chevys back then, too. Never found a good dealer out there. Maybe check with GMC or Cadillac dealers since they're more "upscale" and kissing butt is more important to those who spend more money on the exact same product you have. Dealer that told you the Pulsar voids your warranty is full of crap. It doesn't. They'd have to prove it caused a failure to deny warranty coverage. This is covered in federal law called the Magnuson-Moss Warranty Act. I recommend reading it and getting familiar with the law so you can call BS on dealers that try that crap. I've had to drop a copy of that on the service writer's desk a couple of times to remind them of how stupid they are for saying things like that. I suspect if I didn't move every couple of years I wouldn't have to flex so much with those guys, but it is what it is. Getting ready to move from California to Florida in a couple of months.