This ignition coil generates the high-voltage pulse required to fire the spark plug in the engine's combustion chamber. It converts the low-voltage supply from the vehicle's electrical system into the stepped-up voltage needed to ionize the spark gap. A failing coil typically causes a misfire under load, rough idle, or a no-start condition because the secondary winding cannot sustain the required voltage. The manufacturer's original coil matches the electrical characteristics and mounting geometry of the assembly, ensuring the ignition timing and spark energy remain within the engine control unit's calibration.