A TBA is a "to be announced", which means they are going to supply the identity of the part later, which makes it more difficult to elaborate on the install procedure. Or it could be a throttle body actuator, aka TB, ETA, EA, etc. etc. Anytime you see a mysterious 2 or 3 letter acronym it's probably for one of these. Does the car have ASR? Non-ASR TBAs rarely fail, just need to be cleaned occasionally and sometimes rewired.