TECHNICAL DESCRIPTION
- The ECM effects air/fuel ratio feedback control in accordance with the signals from the linear air-fuel ratio sensor.
- If the linear air-fuel ratio sensor has deteriorated, corrections will be made by the heated oxygen sensor (rear).
DESCRIPTIONS OF MONITOR METHODS
- If the air-fuel ratio detection signal has an abnormality although the linear air-fuel ratio sensor is sufficiently ready to operate, the DTC is set as a malfunction.
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Linear air-fuel ratio sensor heater monitor
- Misfire monitor
- Fuel system monitor
Sensor (The sensor below is determined to be normal)
- Mass airflow sensor
- Engine coolant temperature sensor
- Intake air temperature sensor
- Barometric pressure sensor
- Throttle position sensor
- Accelerator pedal position sensor
Check Conditions
- Battery positive voltage is between 10 and 16.5 volts.
- More than 60 - 308 seconds have passed since the engine starting sequence was completed.
Judgment Criteria
- The negative circuit voltage subtracted from the pumping circuit voltage is be lower than -2.1 volts or higher than 2.3 volts for 12 seconds.
- The pumping current is be lower than 0 milli ampere or higher than 0 milli ampere for 12 seconds.
FAIL-SAFE AND BACKUP FUNCTION
- Does not control air-fuel ratio closed loop.
OBD-II DRIVE CYCLE PATTERN
- Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 21 .
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Linear air-fuel ratio sensor failed.
- Connector damage.
- ECM failed.