What's the steady state charge of your battery? 2 hours after a load it should be 12.6V to 12.9V. If you don't have a voltage meter you can put the truck in Service Mode to check the battery voltage. I had to install a battery maintainer on my truck but since doing so all my electrical issues are fixed.

 

Your Battery is not getting fully charged
How often is your truck driven?
How long is it driven when it is driven?

It takes at least 20 to 30 Minutes of Driving for a Battery to Recharge after Starting Up
You might need to get a Battery Charger/Maintainer to make sure you battery fully charges

Also your Brake Booster and Master Cylinder Both are now using Electrical Power
So, not enough charge in the battery
Will cause issue for the brake system

 

The service paperwork shows 12.2 volts for the old battery. I have an electricians multimeter which I’m sure I can use. If the truck were outside of warranty, I’d consider the maintainer, but I’m of the mindset that I shouldn’t need to with it being less than a year old and it’s not sitting for long periods.

 

My truck was made in June and I bought it in November so it sat somewhere without the battery being charged for 5 months. I have many vehicles and I'm retired so the truck sits a lot and when I do go somewhere it's less than 4 miles. I already had the maintainer on my generator battery so I bought the leads for the truck and swap it back and forth. When I first hooked it up the battery needed to be charged every night. After 3 months it only needs to be charged up once a week now. There are numerous parasitic draws on these trucks including the security, the internet connection, looking for a remote start signal from the app or the remote and looking for an OTA update. It even has a humidity sensor that moves vent doors when the truck is off. I'm retired and have nothing better to do than mess with my toys. These batteries start to sulfate when they're not charged to 12.4V. I understand your position but my own thought is GM (I'm a retired GM Engineer) is going to be replacing a lot of batteries under warranty and owners will be afterwards. Just a thought.

 

It's silly that these new trucks need anything aftermarket for them to work reliably. Anyone should be able to park their truck for 10 to 15 days and it fires up. So if I had one and I leave my truck at airports for 14 days at a time I'd be stranded???

 

After doing a few months of checking my own truck, I can tell you the battery voltage drops .2 volts every day from just having the security turned on.
The updates don't work once the battery has dropped 30% from steady state of 12.6 to 12.9V . While that doesn't make the truck undrivable and it will start ... it's not good for the life of the battery as they start to sulfate at 12.4 volts. I'm a long retired GM Engineer and it aggravates me to death.

 

Verdict is in. Apparently a known issue with a version of the brake system software. They did an update and a relearn on the brake system plunger.

Regardless, I am looking at buying one the NOCO Genius Gen5X1 maintainer.

 

Glad it is sorted out
Thanks for updating

 

I parked my 24 canyon in the garage in NC last winter for almost 4 months, with it locked and armed, and had no issues. Started right back up when I got back.

 

The starter requires ~200 amps. These are 800 CCA batteries (will supply 800 amps for 30 seconds at 0 degrees Fahrenheit and maintain more than 7.2 Volts) . Or, ~1000 CA.
A good battery and new starter will allow a vehicle to start with only 9.6V.
The trucks have a Battery Maintenance Mode when the Security is on. It shuts down all the parasitic draws except the Security.
If the battery gets low enough where the Security won't work the alarm will go off. You'll get an email if you've set it up to do so.

 

Just recently had this happen to me last week. On Thursday I went to the parking lot to turn in my truck and it took longer than normal to turn over and I got these same error messages you did. In the days/weeks prior I was also getting little strange messages but they went away in seconds. This time I had a CEL and the brake system code as well. The dealer said my battery was not holding sufficient power anymore (12 volts) so they replaced it and it’s been smooth sailing for the last 5 days. I have been turning off auto stop-start and I turned off auto updates let’s see if the problem is gone.

 

If you ever get 'little strange messages' ... turn the truck off, put it in Service Mode and check the Battery Charge screen.
A healthy AGM battery should have a steady state charge of 12.6 to 12.9 volts.