Electronic Ignition System Diagnosis (4.2L): Description

Electronic ignition system uses an individual ignition coil for each cylinder. Powertrain Control Module (PCM) controls ignition operation through 6 Ignition Control (IC) circuits. Each ignition coil is connected to PCM, power, or ground by the following circuits:

• Ground.
• Ignition 1 voltage.
• Appropriate IC Control circuit.

PCM triggers an ignition coil by grounding appropriate IC Control circuit using information from Crankshaft Position (CKP) and Camshaft Position (CMP) sensors.