TrailBlazer 4WD L6-4.2L VIN S (2002)
Ignition Coil: Description and Operation
Each ignition coil has an ignition 1 feed and a ground. The PCM supplies an ignition control (IC) circuit. Each ignition coil contains a solid state driver
module as its primary element. The PCM signals the coil driver to initiate a firing event by applying the IC circuit voltage for the appropriate time or
dwell. When the voltage is removed, the coil fires the spark plug. The coils are current-limited to prevent overloading if the IC current is held high too
long. The spark plugs are tipped with platinum for long wear and higher efficiency.
