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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 382 (Engine Controls - Basic Diagnostic Procedures) >> Ignition Systems >> Electronic Ignition System Diagnosis >> Circuit Description
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Circuit Description

WARNING: This page is about a different car, the 2003 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

There are 2 separate ignition module assemblies, one for each bank of cylinders. Each assembly contains an ignition control (IC) module and 4 ignition coils. Both IC modules consist of the following circuits:

Each ignition coil connects directly to its spark plug through a wire spring conductor housed in a short spark plug boot. The IC circuits transmit timing pulses from the Powertrain Control Module (PCM) to the IC modules which triggers the ignition coils in the proper sequence for spark plug firing. The PCM monitors each IC circuit for improper voltage levels. If an improper voltage level is detected on an IC circuit, a DTC will set.