Operation and testing coil over plug ignition (4 wire) – Toyota/Lexus

This case study is perfect for anyone interested in the working details of Toyota/Lexus coil over plug ignition system, and the very similar three-wire designs used by many other manufacturers. We spend a lot of time with the Pico on this one, but don’t forget the other basic checks I discuss, including the spark output, power balance and moving a suspected bad coil to another cylinder.