Computerized Engine Controls: Notes

The Electronic Concentrated Engine Control System (ECCS) module may also be referred to as an Engine Control Module (ECM). ECM is the heart of the ECCS computerized emission, ignition and fuel control system. ECM accepts input voltage signals from a variety of input components. ECM compares each voltage input signal to a parameter which is preprogrammed into ECM. It instantly analyzes each of the input voltage values and adjusts output voltage signals accordingly. This allows optimum vehicle performance under a wide variety of operating conditions.

Voltage to ECM, and components requiring battery voltage, is supplied by ECCS relay. Relay is used to protect ECM in the event of reverse polarity at battery cables. To determine power distribution to ECM components on specific models, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.