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:

    If you think something is wrong
    If you notice any of the following symptoms, your vehicle probably needs adjustment or repair. Contact your Toyota dealer as soon as possible. Visible symptoms ● Fluid leaks under the vehicle. (Water dripping from the air conditioning after use is normal.) ● Flat-looking tires or u ...

    Inspection procedure
    Hint: if dtc p0441 (purge flow), p0446 (vsv for ccv or vsv for pressure switching valve), p0451, p0452 or p0453  is output with dtc p0442 or p0456 , first troubleshoot dtc p0441, p0446, p0451, p0452 or p0453. If no malfunction is detected, troubleshoot dtc p0442 or p0456 next. ...

    Seat heaters
    Press the switch. 1 High temperature 2 Low temperature The indicator light comes on when the switch is on. ■The seat heaters can be used when ► Vehicles without a smart key system The engine switch is in the “ON” position. ►Vehicles with a smart key system The engine ...