Computerized Engine Controls: Notes

The Electronic Concentrated Control System (ECCS) is a computerized emission, ignition, and fuel control system. A single Electronic Control Unit (ECU) uses input voltage signals received from various input components to control output. ECU compares each input signal to the appropriate parameter preprogrammed in ECU and adjusts output voltage signals accordingly. This allows optimum vehicle performance under various operating conditions.

Voltage to ECU and components requiring battery voltage is supplied by a safety relay and/or a main relay. Safety relay is used to prevent damage to ECU in the event of reverse polarity at the battery cables. To determine power distribution to ECCS components on specific models, see appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.