I have a 2019 JLU Sport S and recently I'm getting some weird messages across my screen, check engine, start stop system failing, ess, shifter, abs. While sitting in line yesterday at McDonald's drive through everything went haywire - speeedometer bottomed out, it was surging, put it in park and then couldn't get it out of gear, it shut off then started back up - 4 way flashers barely worked. We had bought a new main battery the day before, so went home and put that in. Called the dealer this morning to have them replace the aux battery and the lady said it's under the driver's seat. Funny the manual shows it under the main battery.