Computerized Engine Control System Description

Computerized engine controls are used to reduce hydrocarbon (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) emissions. Also taken into consideration are driveability and fuel economy.

In addition to controlling throttle positioner and other emission components, Tercel ECU also controls a Feedback Control (FBC) system. By monitoring a signal from Oxygen (O2) sensor, Electronic Control Unit (ECU) can determine necessary changes to the air/fuel mixture.

The ECU on Pickup models controls emission components only. Idle speed and air fuel/mixture are controlled through mechanical adjustments of carburetor.