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

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    How to proceed with troubleshooting
    The hand–held tester can be used at step 4, 6, 8 and 9. 1 Vehicle brought to workshop 2 Customer problem analysis 3 Warning light check 4 The dtcs check (present and past dtcs) 5 The dtcs chart 6 Circuit inspection 7 Repair 8 Clear the dtcs (present and past dtcs) 9 The dt ...

    Precaution
    Caution: the corolla is equipped with srs, which comprises a driver airbag, front passenger airbag and side airbag. Failure to carry out service operations in the correct sequence could cause the srs to unexpectedly deploy during servicing, possibly leading to a serious accident. Fu ...

    Inspection
    1. Cooler thermistor no.1 Check resistance between terminals 1 and 2 of cooler thermistor no. 1 At each temperature, as shown in the chart. Resistance: If resistance value is not as specified, replace the sensor. 2. Cooler and accessory assy Inspect blower switch contin ...