Possible Causes
Intake air leaks
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Air Flow (MAF) sensor
Incorrect Positive Crankcase Ventilation (PCV) hose connection
الأسباب المحتملة
Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
Excessive Fuel Consumption
الأعراض المحتملة
Description
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closer to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the Malfunction Indicator Light (MIL) (2 trip detection logic). The Diagnostic Trouble Code (DTC) will be set when the fuel injection system does not operate properly, or the amount of mixture ratio compensation is too small. (The mixture ratio is too lean.)
