Hi all, I’ve got a 2018 w the 3.6 and 34k. I rarely if ever heard it auto stop/start for the first 2 years I owned it. I recently plugged a code scanner into the OBD and lo and behold it began working. It worked a few weeks and stopped again. Just for the heck of it, I tried plugging in the code scanner again and sure enough it immediately started working again.
I get no DTCs but do see a few emissions red lights on my scanner which it’s incapable of clearing.
Anyone else run into this or have any suggestions. I do see my fuel economy goes up about 1mpg when it’s working.

 

Auto Start/Stop is the first thing the Battery Management System shuts down if battery state of charge is less than optimal. When I was commuting every day, my A.S.S. always worked (when I checked - I normally have it turned off). Since I haven't been driving my truck every day, and many trips are just a couple miles, it usually doesn't work. Then I put a charger on the truck overnight, or take a longer drive, and it starts working again for a while. That doesn't mean there's anything wrong with the battery - the truck just isn't being driven enough to fully recharge it after sitting idle (during which the battery is still being used by some of the electronics) and being started for the short trips. If you make a lot of short trips around town and want A.S.S. to work all the time, get a Battery Tender, Noco Genius or CTEK charger and use it on a regular basis. No idea why plugging into the OBD port might trigger it working.

 

There are multiple things that could effect A-S-S. Since it involves the BMS (Battery Management System) which is an integral part of the BCM (Body Control Module), a standard OBDII code reader will not read DTCs from the BCM. You need FORScan or a scan tool to read all the DTCs that your truck can broadcast.