Toyota Corolla (E120): Circuit description

The ignition switch provides circuit power and the ecm provides the circuit ground that illuminates the mil.

Mil operation is checked visually: it should be illuminated when the ignition is first turned on. If the mil is off all of the time or on all of the time, use the procedure below to troubleshoot it. The mil is used to indicate the ecm’s detection of a vehicle malfunction.

Follow this procedure using the hand–held tester or an obd ii scan tool to determine the cause of the problem and to check the mil.

Wiring diagram

Inspection procedure

    Share this page:

    Other materials:

    For vehicles equipped with srs airbag and seat belt pretensioner
    Hint: the vehicle is equipped with an srs (supplemental restraint system), such as the horn button assembly, the instrument panel passenger airbag assembly, the front seat airbag assembly, the center airbag sensor assembly, the front airbag sensor, the side airbag sensor and the seat belt p ...

    Circuit description
    The srs warning light is located on the combination meter. When the srs is normal, the srs warning light lights up for approx. 6 Seconds after the ignition switch is turned from the lock position to on position, and then turns off automatically. If there is a malfunction in the srs, the srs ...

    Emission inspection and maintenance (I/M) programs
    Some states have vehicle emission inspection programs which include OBD (On Board Diagnostics) checks. The OBD system monitors the operation of the emission control system. If the malfunction indicator lamp comes on The OBD system determines that a problem exists somewhere in the emission cont ...