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 stored 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 220 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 milliampere or higher than 0 milliampere 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 22 
. 
TROUBLESHOOTING HINTS (The most likely causes for this code to be stored are: )
- Linear air-fuel ratio sensor failed.
 - Connector damage.
 - ECM failed.