Quoted from LTG:

Software will tell you. Go to Tests - Coils - stop left sling. Hit that start button, then start hitting the + diagnostic button. This steps you through coil, wiring, drive transistor, fuse, connector info.
Unless you have other coils not working, forget the fuse. And unless the coil is fried, probably not the transistor.
Most likely a broken wire at the coil, carefully dig around the thin wires going from the coil to the lugs, they can be cracked or broken and hard to see, or following the same color wires a wire came off of another coil where you have two wires to one lug.
LTG : )