Oldsmobile/Buick Repair: Olds 88, 1995, brake booster, traction control

Question
When engine off key out of egnition a motor was running, drive side under air intake. I belive ABS motor, when car running brakes hard to push. Could it be traction control?
How hard and how much should I expect to pay for ABS motor replacement or Traction control?
I had to disconet the battery to get motor to stop running.

Answer
hi t,  well sounds like brake booster.try tapping on this mtr see if it shuts off if you notice when you push the brakes this motor will run .could be booster or abs pump if abs pump very expensive hubdreds if booster prob 100 or so.good luck please rate my help ty billymac