Run Mode

The Run Mode has two conditions: "Open Loop" and "Closed Loop". When engine is first started and engine speed is above 400 rpm, system goes into 'Open Loop' operation. In "Open Loop", PCM ignores signals from O2 sensors and calculates required injector pulse width based primarily on inputs from MAP, LAT and ECT sensors. The system will stay in "Open Loop" until following conditions are met:

• The O2 sensors have varying voltage output, showing that they are hot enough to operate properly.
• The ECT sensor indicates above 80°C.
• A calibrated time delay has elapsed after starting engine. This delay allows all sensors to stabilize.

When these conditions are satisfied, PCM goes into "Closed Loop" operation. In "Closed Loop", PCM adjusts calculated injector pulse width for each bank of injectors based on signals from each O2 sensor.