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:

    Basic repair hint
    (A) hints on operations 1 Looks Always wear a clean uniform. Hat and safety shoes must be worn. 2 Vehicle protection Set a grill cover, fender cover, seat cover and floor mat before starting the operation. 3 Safe ...

    Inspection procedure
    1 Inspect fuse(ecu–ig fuse) Remove ecu–ig fuse from the instrument panel j/b.  check continuity of ecu–ig fuse. Ok: continuity 2 Inspect battery Ok: voltage: 10 – 14 v 3 Inspect skid control ecu connector(ig1 terminal voltage) In case of using hand–held te ...

    Circuit description
    The ecm compares the two waveforms of the heated oxygen sensors located before and after the catalyst to determine whether or not the catalyst performance has deteriorated. Air–fuel ratio feedback compensation keeps the waveform of the heated oxygen sensor in front of the catalyst alterna ...