Bump... I'm having the issue too but only when the car is fully warmed up. I get charging system malfunction on the DIC too if the car is fully warmed up and I turn it off and start it back up within a few minutes.. I'm thinking when the voltage of my car drops below 11.4 volts it's dropping the voltage of the brake circuit too causing the P0703 to pop pop.. when I scan for trouble codes the P0621 pops up first and the P0703 after.. I'm almost positive it's the current sensor acting up since I have a charging issue and brake signal issue when both use the 10 volt reference wire of the BCM . Odd thing is if I bring the rpm up to 1500 for a second and let off the gas the alternator starts charging properly and voltage goes up...
When it's not charging properly the scanner data shows 15% in the f terminal of the alternator, a a quick tap of the gas it will go up to 50%. Also it seems to only happen when the car charging system seems to be in the maintenance mode where no matter what the electrical load is it maintains 12.8 volts
