The Catera 3.0L V6 is equipped with a distributorless ignition system. The system has 2 ignition coil packs. One coil pack is for bank 1 (cylinders 1, 3, and 5), and the other coil pack is for bank 2 (cylinders 2, 4, and 6). Each coil pack contains 3 coils, one for each cylinder on the bank. At the end of each coil is a boot, which connects directly to the spark plug. This eliminates the need for a spark plug wire, and the result is more precise ignition timing.
The engine control module (ECM) contains the ignition control module. The module precisely controls the ignition timing.