Ignition Coil

Ignition coils are inductive components transforming low-voltage primary circuit electricity into the high-voltage pulses needed to create an arc at the spark plug gap. These coils are integral to both distributor-based and distributorless ignition systems, commonly located near the spark plugs or within the engine control module housing. Modern designs utilize primary and secondary windings with specific resistance values to achieve required dwell and output voltages. Coil construction varies, employing materials like ferrite or oil-filled casings for thermal management and dielectric strength. Failure modes typically involve open or shorted windings, leading to misfires or no-start conditions, and are diagnosed via resistance measurements and visual inspection for cracking or arcing.