P0700 is just the PCM telling you that a fault code is present in the TCM. That may be the P0882 code.
P0882 is the 'TCM input voltage low'. The new alternator seemed to make a difference. I have heard of broken/corroded wires in the harness terminals that can be intermittent around the battery tray. Anywhere around the battery is a corrosive area over the years.
13.6 is a fair charging voltage. What happens if you turn on the headlights and rear defroster?
12.3 is too low for a charging battery. It should closely match what the alternator is putting out.
I see a discussion here about a PT with P0882:
P0882 Low input signal - PT Cruiser Forum
I totally agree with diagnosing this first and not just changing parts without proof or confirmation.
P0882 is the 'TCM input voltage low'. The new alternator seemed to make a difference. I have heard of broken/corroded wires in the harness terminals that can be intermittent around the battery tray. Anywhere around the battery is a corrosive area over the years.
13.6 is a fair charging voltage. What happens if you turn on the headlights and rear defroster?
12.3 is too low for a charging battery. It should closely match what the alternator is putting out.
I see a discussion here about a PT with P0882:
P0882 Low input signal - PT Cruiser Forum
I totally agree with diagnosing this first and not just changing parts without proof or confirmation.