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:

    Check and replace ecu
    Notice: start an inspection of the connector from the backside of the connector on the wire harness side with the connector connected to the ecu. When no measurement condition is specified, perform the inspection with the engine stopped and also the ignition switch on. First check the ec ...

    On–vehicle inspection
    1. Check cooling fan operation with low temperature (below 83 c (181 f)) Turn the ignition switch on.  check that the cooling fan stops. Hint: if not, check the cooling fan relay and water temperature sensor, and check for separated connector or severed wire between the cooling fan ...

    Circuit description
    The seat belt buckle switch (lh) circuit consists of the airbag sensor assy center and front seat inner belt assy (lh). Dtc b0126/b0127/27 is recorded when a malfunction is detected in the seat belt buckle switch (lh) circuit. Wiring diagram ...