torque converter will not lock

1993 a4 formula

torque converter will not lock at all fluid is good and it is all stock and throwing no codes

Um...the most obvious is often overlooked. Check for a blown fuse. Have it scanned and see if the computer is commanding lock-up. Many parameters need to be met for the computer to send the command. Bad brake light switch? Bad connection at case connector? Bad lock-up solenoid? Stuck TCC valve? Bad converter clutch?

Frank
CPT