What code should I really start with if anyone can help

[7thavepain]

 

[JasonH]

Battery voltage. A weak battery can make other systems go haywire. I kept getting intermittent Advancetrac warnings on my 2017. They would randomly appear, with no common cause that I could identify. I changed the battery when it began to die repeatedly after the vehicle sat for several days. Haven't received a warning since.

 

[Mr Big]

Battery voltage. A weak battery can make other systems go haywire. I kept getting intermittent Advancetrac warnings on my 2017. They would randomly appear, with no common cause that I could identify. I changed the battery when it began to die repeatedly after the vehicle sat for several days. Haven't received a warning since.

I agree. I was messing around with my vehicle modifying a few things and my battery drained down to where the vehicle would not start.
After charging the battery, when I started the Expedition, it ran rough and I had the check engine light on. I loaded up FORScan, to check the codes, and there were over 20 fault codes, one being severe, (Catalytic Converter failure). So, I erase all the codes and reset the PCM and TCM learn memory. The vehicle ran perfectly and no codes came back.
Never underestimate the power of the battery on these beasts.