Display Group 07, Field 4, Oxygen Sensor Learning Requirement Display (Cyls. 1-3)

This field is an expanded version of FIELD 3. Ensure no codes are set and engine coolant temperature is 176-221°F (80-105°C). If learning does not begin with coolant at specified temperature, snap throttle. If learning does not begin, ensure idle speed is 700-800 RPM. Idle speed must be steady. While driving vehicle, increase engine speed from 1500 RPM to 3000 RPM, lightly applying brakes to load engine.
Displayed value should be 11111111. Each of these eight digits represents a learning range. See OXYGEN SENSOR LEARNING REQUIREMENT DISPLAY table. A "1" indicates learning has occurred. A "0" indicates learning has not occurred. If displayed value is not 11111111, further diagnosis is necessary.
Learning will not occur if a difference between richest and leanest oxygen sensor learning values of one display group is at least 9 percent. Learning begins 20 seconds after initiating basic engine setting and/or 2-4 minutes after engine starting.
After basic engine setting has been initiated, all learning ranges are set to "0" to force new learning in all 8 ranges. New learning (learning requirement) is forced after each engine starting, when engine coolant temperature is less than 104°F (40°C).
When engine coolant temperature at 104°F (40°C) or greater, new learning is forced only at idle after each engine starting. If difference between stored learning value and new learning value is great enough, all learning ranges are reset to "0".

OXYGEN SENSOR LEARNING REQUIREMENT DISPLAY

NOTE: Before evaluating Oxygen Sensor (O2S) control, ensure successful O2S learning has occurred.