OK- followup Q:
Where are you looking and what red bar are you referring to when you are looking at the SOC meter/battery meter?
Are you looking at a yellow/black charger?
Can you post a pic?
How would we know? Is 2003 a T2 car? If so, battery soc comes from controller.
If T3+ car, soc display is determined from the proper charger and psdm.
Now we get it. Battery status communication is from T2 to display on the 12p connector.
Programming is through Sentry sw.
I replied previously about the start sequence and precharge to pull in contactor, but P1, P2, have different function than with T4. Pin 17 not used, Pin11 is coil driver in T2.