I need some advice on a puzzling issue with my 2019 Model S. The HV battery was replaced under warranty in 9/2023, followed by a 12V battery replacement in last month (12/2023) due to issues with not starting intermittently and the mobile service attributed to the 12V. Just after crossing 50,000 miles this month and exiting warranty, my car refused to go into drive, throwing codes and eventually blacking out of the blue.
Tesla roadside service pointed to a dead 12V battery, since it was recently replaced it would be covered under warranty. When it was towed, they did boost the battery and everything did seem to work. After diagnostics at Tesla, Tesla confirmed that the 12V battery is dead again and will be replaced under warranty, but they also found the onboard charger to be faulty, costing $3,000. I'm baffled because I never experienced any charging problems - at home or with superchargers.
Has anyone faced a similar situation or have insights on whether a faulty onboard charger could cause a 12V battery to die? Did the initial 12V battery failure that was replaced last month hint at this issue? Any advice would be greatly appreciated. Thanks!
Tesla roadside service pointed to a dead 12V battery, since it was recently replaced it would be covered under warranty. When it was towed, they did boost the battery and everything did seem to work. After diagnostics at Tesla, Tesla confirmed that the 12V battery is dead again and will be replaced under warranty, but they also found the onboard charger to be faulty, costing $3,000. I'm baffled because I never experienced any charging problems - at home or with superchargers.
Has anyone faced a similar situation or have insights on whether a faulty onboard charger could cause a 12V battery to die? Did the initial 12V battery failure that was replaced last month hint at this issue? Any advice would be greatly appreciated. Thanks!