Chosen Solution
I have noticed through iStat Menus that the P-bus value is fixed around 12.15 V. Is that normal?
@sa46851 is the MacBook working fine, with no issues? If so, it is probably normal; some iStat sensors are always maxed out. I have not got a 2010 15" to compare this to.
PPBUS_G3H is suppose to be 12.56 volts. However, if your computer is working and has a green light in the charger and no signs of trouble there is no way it can be 12.16 v. If you want to know the true voltage, take the bottom cover off and measure voltage at the backlight fuse near the LVDS connector. It will have a “P” on it.
