Ignition Coil: Description and Operation
IGNITION COILBattery voltage is supplied to the ignition coil positive terminal from the Automatic Shutdown (ASD) relay
The Powertrain Control Module (PCM) opens and closes the ignition coil ground circuit for ignition coil operation.
Base ignition timing is not adjustable on this engine. By controlling the coil ground circuit, the PCM is able to set the base timing and adjust the ignition timing advance. This is done to meet changing engine operating conditions.
The ignition coil is not oil filled. The windings are embedded in an epoxy compound. This provides heat and vibration resistance that allows the ignition coil to be mounted on the engine.
CIRCUIT OPERATION
When the Automatic Shut Down (ASD) relay contacts close, they connect circuits A16 and A142. Circuit A142 splices to supply voltage to the ignition coil. The Powertrain Control Module (PCM) controls the ground path for the ignition coil on circuit K19. Circuit K19 connects to cavity A7 of the PCM.