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:

    Inspection
    1. Inspect driver’s door lock Inspect the door lock motor operation. Standard: If the result is not as specified, replace the door lock assembly. Inspect the door lock and unlock switch continuity. Standard: If the result is not as specified, replace the door lock assem ...

    Circuit description
    In the diagram below, when the engine is cranked, current flows from terminal st2 of the ignition switch to the starter relay coil and also current flows to terminal sta of the ecm (sta signal). When the sta signal and ne signal are input to the ecm, tr is turned on, current flows to the c ...

    Favorites list setting
    Up to 15 contacts (maximum of 4 numbers per contact) can be registered in the favorites list. ■ Registering the contacts in the favorites list 1 Select “Add Favorite”. 2 Select the desired contact to add to the favorites list. Dimmed contacts are already stored as a favorite. 3 Chec ...