Ignition System - 2.5L/3.9L/5.2L: Description
Electronic Spark Control system features a Hall Effect distributor and a Single Module Engine Controller (SMEC). The heart of the system is the SMEC. It provides an infinite number of variable advance curves depending upon engine operating conditions. This allows ignition of lean air/fuel mixtures in accordance to different modes of engine operation.
SMEC contains a built-in microprocessor which continually receives input voltage signals from various engine sensors. An analysis of these voltage signals determines current engine mode and the SMEC responds by electronically advancing or retarding ignition timing. SMEC determines when ignition is required and signals ignition coil to produce electrical impulses that fire the spark plugs.
Up to 4 engine sensors input information to the SMEC. These inputs include coolant temperature, engine RPM, manifold vacuum and exhaust oxygen content. The SMEC is located inside of the left front fenderwell.