Avalanche 2500 4WD V8-8.1L VIN G (2003)
Ignition Coil: Description and Operation
Ignition Coils
Ignition Coils
The following are the 2 different manufacturers for the ignition coils.
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Melco (1), square design
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Delphi (2), round design
These 2 coils use 2 different spark plug wire lengths, and mounting brackets.
Each ignition coil has an ignition 1 feed and a ground. The PCM supplies a low reference and an ignition control (IC) circuit. Each ignition coil contains
a solid state driver module as the 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.
