Got my Jeep back earlier this week. The report from the dealer found:
Intermitant slow response from ASD Power to PCM Circuit K51. Found intermitant open on ASD circuit under fuse box to the right side. PCM was still intermitant, likely due to the open in the ASD circuit. Replaced PCM module...
Have owned my 2021 Willys Gladiator Ecodiesel for 6 months, approx 6700 miles. Started getting a Charging System callout in the MOPAR vehicle health report. ESS system was not operational as well.
Had the ESS system issue a little over a month ago, but the dealer tested and said it was ok...
I believe this was in relation to the start/stop system and the aux battery that is used for that. My start/stop system was acting the same way saying the battery was not charging. My 2016 has an aux battery for the start/stop system. Reference...
I had this same issue with my 2016 Cherokee. Battery kept saying it was charging. Dealership replaced the battery, same indications. Further troubleshooting pointed to the AUX battery charging circuit off of the alternator. Once they replaced that, the system charged and has worked like a champ...