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:

    Vehicle control system
    Ignition or starter switch assy Replacement 1. Remove steering column cover 2. Remove ignition or starter switch assy Disconnect the ignition switch connector and unlock warning switch connector.  remove the 2 clamps.  remove the 2 screws and ignition switch. Inspectio ...

    Inspection procedure
    1 Inspect stop lamp switch assy Check that the stop light lights up when brake pedal is depressed and turns off when the brake pedal is released. 2 Inspect skid control ecu terminal voltage(stp terminal) Disconnect skid control ecu connector. measure voltage between termina ...

    Circuit description
    Refer to dtc p0120 Dtc no. Dtc detection condition Trouble area P0121 The following condition is met 4 times. After the vehicle speed has exceeded 19 mph (30 km/h) once, the throttle position sensor output value is out of normal range when the throttle ...