Electronic Ignition System Diagnosis (2.2L): Description

WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2002 Saturn Vue, 2002 Pontiac Montana, 2002 Pontiac Aztek, 2002 Oldsmobile Silhouette, and 2002 Oldsmobile Bravada. However, it is still accessible from the selected car via links, so may be relevant.

The Ignition Control (IC) module has independent power and ground circuits. The circuits between IC module and Powertrain Control Module (PCM) consist of the following:

Low reference circuit.
Low resolution engine speed signal.
Two IC timing control signals for cylinders No. 1 and 4, and for cylinders No. 2 and 3.

IC module and PCM use low resolution engine speed signal to control ignition operation. Low resolution engine speed signal is derived from Crankshaft Position (CKP) sensor, which is connected directly to IC module.