Toyota Corolla (E120): Problem symptoms table

The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to troubleshoot the problem when a normal code is displayed in the diagnostic trouble code chart but the problem is still occurring. Numbers in the table indicate the order in which the circuits or parts should be checked.

Hint: when the problem is not detected by the diagnostic system even though the problem symptom is present, it may be that the problem is occurring outside the detection range of the diagnostic system.

Circuit inspection

    Share this page:

    Other materials:

    Circuit description
    The intake air temperature (iat) sensor, mounted on the mass air flow (maf) sensor, monitors the intake air temperature. The iat sensor has a thermistor that varies its resistance depending on the temperature of the intake air. When the air temperature is low, the resistance in the thermisto ...

    Dtc check/clear
    Notice: if there is no dtc in the normal mode, check the pending fault code using the continuous test results function (mode 7 for sae j1979) on the obd ii scan tool or the hand–held tester. Hand–held tester only: when the diagnosis system is switched from the normal mode to the ...

    Monitor description
    While the engine is being cranked, the battery positive voltage is applied to terminal sta of the ecm. If the ecm detects the starter control signal (sta) while the vehicle is driving, it will conclude that there is a fault in the starter control circuit. The ecm will turn on the mil and a d ...