I used it the other day to diagnose my A4, MAP sensor was bad, a $38 fix. Once I unplugged the glove box switch and light, the fuse stopped blowing.
Some faults were too generic to find (like my courtesy light failure, merely said ground or open fault-but other posts on this forum led me to a faulty switch in the glove box. Some of the information is hard to find, like how to reset my top fault, but finally found it and got it sorted. Identified all kinds of issues (including some I didn't even know I had). I've had mine a couple of months, can't believe I didn't have one years ago.
