Ignition Coil: Description and Operation
IGNITION COILSThe Ignition System uses a ignition coil assembly for each bank. Each ignition coil assembly consist of 3 ignition coils. The ignition coil assemblies consist of the following circuits:
- An ignition voltage circuit
- A ground circuit
- An ignition control (IC) circuit for each ignition coil
The ignition coil assemblies are mounted in the center of each camshaft cover with short boots connecting the coils to the spark plugs. The engine control module (ECM) primarily uses engine speed and position information from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor to control the sequence, dwell, and timing of the spark. The ECM can command each ignition coil ON/OFF by grounding the IC circuit of the ignition coil. The IC circuits are pulse width modulated (PWM) in order to precisely control the spark events.