The light turn on VC and the car skip

Hello, It sounds like the computer thinks the vehicle is slipping, so it is reducing power, which causes the pulsating power you are mentioning. This is normally due to a faulty wheel speed sensor, and you will need to have diagnostics ran to ensure a proven fix. Try one of these shops in the link, they are all RepairPal certified shops with excellent training and equipment. http://repairpal.com/cadillac-within-10-miles-of-fort-worth-texas-76107