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MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS TSB Revision MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE> 13A-221 DTC SET CONDITIONS Logic Flow Chart . Check Conditions • Engine coolant temperature is higher than 60°C (140 °F). • Engine speed is between 1,200 and 3,000 r/min. • Volumetric efficiency is between 25 and 60 per- cent. • Under the closed loop air/fuel control. • The accelerator pedal is open. • Short-term fuel trim is between −25 and +25 per- cent. • More than 2 seconds have elapsed after the above mentioned conditions have been met. • The PCM monitors for this condition for 7 cycles of 10 seconds each during the drive cycle. Judgment Criteria • The cylinder 1, 4 heated oxygen sensor (front) sends "lean" and "rich" signals alternately 9 times or • The cylinder 1, 4 heated oxygen sensor (front) sends "lean" and "rich" signals alternately 11 NOTE: If the sensor switching frequency is lower − H02S Test Results, it is assumed that the heated oxygen sensor has deteriorated. If it is . OBD-II DRIVE CYCLE PATTERN − OBD-II Drive Cycle − Procedure 4 − Heated Oxygen Sensor Monitor . F0: THRESHOLD VALUE FOR AVERAGE SWITCHING FREQUENCY START MONITORING CONDITIONS MALFUNCTION GOOD END NO NO YES YES Ff < F0 CALCULATE AVERAGE SWITCHING FREQUENCY (Ff) OVER SPECIFIED TIMES AK302021 |