Have been doing my best to find a previous thread to avoid duplicates but did not have success. 2020 trailboss 5.3, bought in 2021. Dealer claims they put a new battery when I bought it in 2021 just due to it sitting for a long time.
Never had battery issues, a week ago tried to remote start, truck sounded like it wanted to turn over but nothing. Jump in it to start, turned over 4-5 times before starting but it did start. Blamed it on 30 degree Michigan weather. Checked cluster and had check engine light on, showed service ESC message, and gas showed on E even thought it had a half tank.
Drove it to work as I didn’t have time to diagnose, on the way there drove perfectly normal and the gas gauge red normal after 5 minutes of driving. Hooked up a simple scanner tool and got codes C0021 brake booster performance, and general code P25A2. Started normally for next 2 days, check engine light went away and remote start even worked but I still took battery off and took to get tested. Was told battery had 100% charge but had a bad cell which was caused by a faulty truck component.
Since out of warranty took to a local shop by work before heading to dealer $200 cheaper, but all they said was bad battery….
Picked the truck up and drove to work where it sat for 8 hours, after work started slow again but did start. 10 mins later stopped for gas, was stopped maybe 10 mins and would not start without a jump. I would appreciate any advice before the dealer tells me I need 3k in electrical work….