Operation

The Catera ignition system consists of 2 coil packs and the ECM. There is no separate ignition control module. The ECM performs all of the ignition control module functions. The Ignition Coil assembly is powered by an ignition feed circuit. The remaining three wires go to the ECM and are the Ignition Control (IC) circuits. The ECM causes a spark to occur by pulsing an ignition control (IC) circuit, which triggers an ignition coil and fires the appropriate spark plug. The sequencing and the timing are ECM controlled. The ECM uses input from the Crankshaft Position (CKP) sensor, the Camshaft Position (CMP) sensor and the knock sensors in order to appropriately control the ignition system.