Any Chrysler techs on here?

[2QuickZ's]

Have a question about the start/stop system. I am probably one of the few people that actually likes the stop/start system so it seems ironic that it rarely works on our 2018 Chrysler Pacifica. The aux battery died once under warranty and was replaced. It worked for a while after the battery replacement and then more or less stopped working. It mostly just gives the message "Stop/start battery charging" and would randomly work one day and then not work again for months. I had it checked one last time before the warranty was up and they said there was nothing wrong with the battery or the system. It took a good year and a half after the warranty was up before the second aux battery finally died, and of course it was like 4 months after the 3 year warranty officially ended on the replacement battery. No biggie. $100 and 10 minutes worth of work and the new battery is in AFTER I made sure it was fully charged on my battery tender. No more code but the stop/start still didn't work and still just said "Stop/start battery charging." Took a month of driving before it randomly worked for one day and then has not worked again since. Anybody have any idea what is up? Is there a reflash available that makes it a little less sensitive to battery voltage/current? The dealership won't do anything or tell me anything without me paying them a $170 diagnostic fee and I did not find a TSB dealing with this issue.

[CMYZ28]

I've found v53 recall which relates to power steering but they also mention that there are ground issues as part of the repair which could be freaking out the ESS stuff if it doesn't have a great connection.
https://www.google.com/url?sa=t&sour...b1OTsRrAtgBl-s

[1BADAIR]

Unplug the IBS sensor for a few seconds and plug it back in

[1BADAIR]

There are 35ish conditions that have to be met to allow operation . When replacing the battery the IBS should be the first thing unhooked. And the last thing installed. If charging be sure to add voltage behind the sensor. Car side not battery side.

[2QuickZ's]

Thanks, Larry. I did unhook the main battery ground first and reconnected it last when I swapped the aux battery but I did not unplug the sensor. I'll try it. No need to disconnect the battery ground just unplug the sensor for a couple of minutes?

[1BADAIR]

Just the sensor . 10 seconds or so

[2QuickZ's]

Thanks, Larry. I unplugged the sensor yesterday as you suggested. Nothing yet but we haven't put many miles on it since then so I will wait and see. I know from the various searches I have done this system seems to be unpredictable. A number of folks say you need to replace the primary battery at the same time as the aux because it still works well enough to start the car but not well enough for the stop/start to function but I read of other people that replaced both and still had issues. I'm not interested enough in getting it working to spend a couple hundred more on a primary battery when mine still starts the car.

[1BADAIR]

One weekend I may be able to look at it for you