Powertrain Management: Description and Operation

Engine Management System (ECCS) Circuit Diagram:

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 can then 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 Electronic Concentrated Engine Control System (ECCS) consists of sensors which detect the engine condition, the Engine Control Module (ECM) which controls the engine on the basis of the sensor signals, and actuators which operate under control of the ECM. The ECM controls the Fuel Injection, Idle Control, Ignition Timing, Engine Cooling Fan, Exhaust Gas Recirculation, Evaporative Canister, Variable Valve Timing, and Fuel Pump Systems. In addition, the ECM is provided with 2 diagnostic test modes (DTM) to facilitate troubleshooting in case of failure.

In the event of a component or circuit failure of certain sensors or actuators, the ECM is programed with a Fail-Safe feature. This will allow the vehicle to be driven in a limited capacity.