have a new job, miconic a with extended vfac drive. very intermittently, the car will shut down with a ems KSD fault. so far it looks like only at the top landing. what i have found is that the DS5 led on the VEC board will come on, and that drops DS1 led on VEC board which drops brake and controller logs ems KSD fault, it pauses for a few seconds, then levels into floor and ready to go again. I found some info regarding DS5 led on the vec board, and it indicates if it comes on, the 5,15, and 24 volt power supplies from ps1 maybe to low, or to low. I checked 15 and 24, and there right on, i readjusted the 5 volts per directions, adjusted it til M1 contractor dropped out, which is hi limit, then came back down enough to keep 5 volts at MTV board. same outcome. there are some notes regarding maybe the DC bus is not bleeding off correctly, but the car runs fine everywhere else except a hi speed run into the top floor, have only seen it on a hi speed run to top floor. one floor runs to top floor don't seem to cause this. although it may just be a coincidence . any one have any ideas not sure where to go. replace VF2 board, replace VEC board, or something else