The build date is May of 2023. I thought about that since my post. But Iv'e been driving it regurlarly since February 5, 2024. I would think that the battery would have charged by now. So, It sat on a car lot for 9 months. I'll have to let the dealer look at it, UGGHH! Thanks for your reply.
That much time on the lot, and during the summer, is hard on the batteries. They will have some capacity loss that charging is not likely to restore.
Also, I mentioned that merely turning on and of the climate control (in my case fresh air) can also throw the "Not Ready" WITHOUT further explanation. Some seem to deny/disbelieve this.
The long highway driving charged them up enough to satisfy the ESS monitoring system to allow it to work. The 14.3 voltage reading while running shows it is trying to charge the batteries. When the batteries are fully charged, it will drop to around 13 while running.
I'm sure your batteries needed a boost a time or two. It should be under warranty. If it is not feasible to have the dealer look at it, you can put an AGM trickle charger on it over night. If still no ESS, you can try separating the grounds at the main battery and charge them independently and reseting the IBS. You have to be careful not to short the cable when disconnected. Verify that you have disconnected the correct negative cable that goes to the aux and not the one that goes to the fender.
There is no screen for the Aux Battery voltage. The two batteries are paralleled together all the time, except during the Startup Test and when ESS has the engine turned off.
I saw a combined voltage of 14.3VThat's not battery voltage, it's the charging system output. To see battery voltage you need to either check it directly at the battery terminals with a meter or view the voltage display on the instrument cluster with the engine NOT running.Ok,
Best to use a decent meter at the battery terminals, truck off and FOB not in your pocket.
Could be the MAIN battery as well. These monitor battery health and if that main battery is deemed not so great, it can cause things like ESS not to work. Truck may still start.......... people think "truck started, obviously battery is good". No, that is not correct.
You would need to separate the grounds at the main battery. Positive meter lead on the main positive with the negative lead on the main negative post will obviously tell you your main battery voltage. Then you move the negative lead to the aux negative cable that you removed from the main negative post. This will be your aux reading. This is also the way you can charge both batteries separately without removing them from the truck. I would also unplug the IBS connector and the orher negative cable from the main negative post ,(leaving the main connected could mess up your reading).Let the batteries sit after charging for 20 minutes or so before you take your reading.
