Run Mode

The run mode has two conditions: Open Loop and Closed Loop. When the engine is first started and engine speed is above 400 RPM, the system goes into Open Loop operation. In Open Loop, the PCM ignores the signals from the oxygen sensors and calculates the required injector pulse width based primarily on inputs from the MAF, IAT and ECT sensors. The system will stay in Open Loop until the following conditions are met:
^ One oxygen sensor has varying voltage output, showing that it is hot enough to operate properly.
^ The ECT sensor indicates above 80°C.
^ A calibrated time delay has elapsed after starting the engine. This delay allows all sensors to stabilize.

When these conditions are satisfied, the PCM goes into Closed Loop operation. In Closed Loop, the PCM adjusts the calculated injector pulse width for each bank of injectors based on the signals from each oxygen sensor.