Backround:
Ordered - 05/25/2017,....delivered 08/11/2017,....current mileage ( 10/16/2022 ) - 11,684.0 miles.
This truck has never been in for service other than oil & filter changes. The truck rarely sits for more than 2 days.
In early July 2022, started to get a " systems off to save battery " fault message after entering the truck & prior to starting it.
As the truck was due for an oil change in Aug. 2022, & it being ( 5 ) years old, decided to have the battery replaced @ the same time.
The oil was changed & the battery replaced on ( 08/09/2022 ), I reminded the tech to reset the battery minder.
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There were no fault messages between ( 08/10/2022 ) & ( 09/27/2022 ),
...................on ( 09/28/2022 ) I got the same " systems off " message.
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The truck went back to the dealership on ( 10/10/2022 ), spoke to the tech prior to him looking @ the truck, gave him my " battery defective / battery minder not reset " theory. The tech load tested the battery & even though the battery minder WAS RESET, he reset it again.
Went out to start the truck on ( 10/12/2022 ), & got the same " systems off " message again.
I have reviewed other threads on this topic, some suggesting that I don't drive enough for the for the system to charge itself. My current driving habits haven't changed since 1 Nov. 2008, & the truck was fault message free from Aug. 2017 till July 2022.
Will be taking the truck back to the dealership & would like to have some fresh theories about what is going on ?
.....................( electrical troubleshooting is not my strong suit )............thanks in advance for your help..
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Have you checked for DTCs with FORScan or a diagnostic scan tool? I would check the connection to the battery sensor positive post to make sure it is clean and tight. Also check the electrical connector and connector terminals to make sure they are clean and damage free. The BMS (Battery Management System) uses the output of the battery sensor to decide what condition the battery is in. Maybe there is a problem with the sensor. After the above checks, I suggest putting a charger on the battery to make sure it is fully charged and then see what happens.

 

You say your driving habits haven't changed and your truck rarely sits for more than two days and you have only 11.6k miles on the odometer after 5 year. That roughly 2300 miles per year or 44 miles per week. If you drive it 5 days a week, that's only about 9 miles per day.

Rough calculations but just what are your driving habits, daily in miles? Given the milage, I'm surprised you didn't have the message from the beginning.

Did the Dealership check the alternator other than load test the battery? The state of charge on the new battery could have been low to begin with. In order for anyone here to help you troubleshoot what's going on we would need to know voltages before, during a start, after to know what the alternator is putting out. State of after the system has gone into sleep. There may be an abnormal parasitic draw taking place but these are the things as 52merc outlined including codes the dealership should be looking into. You'll need to push them.