Powertrain Management: Description and Operation

ECCS System Input/Output Chart:

PURPOSE
The Electronic Concentrated Engine Control System (ECCS) is used to provide precise control of the air-fuel ratio to the stoichiometric point. The Three Way Catalyst (TWC) can better reduce CO, HC and NOX emissions. The Engine Control Module (ECM) adjusts the injector pulse width according to the sensor input voltages. This maintains the mixture ratio within the range of the stoichiometric air-fuel ratio.

OPERATION
The term used by Nissan to identify the computerized engine control system is Electronic Concentrated Engine Control System (ECCS). This system is comprised of an Engine Control Module (ECM) or central processor, several sensors or input devices and actuators or output devices. All components and circuits must work in conjunction with each other for the system to control emissions and maintain fuel economy and performance at optimum levels. The ECCS system also has built-in Self-Diagnostics and a Fail-Safe system.