Toyota Corolla (E120): Circuit description

When the ignition switch is turned on, battery positive voltage is applied to the coilwhich closes the contacts of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.

This signal causes current to flow to the coil, closing the contacts of the efi relay and supplying power to terminal +b of the ecm.

If the ignition switch is turned off, the ecm continues to switch on the efi relay for a maximum of 2 seconds for the initial setting of the isc valve.

Wiring diagram

Inspection procedure

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    On–vehicle inspection
    1. Inspect speedometer  check the operation. Using a speedometer tester, inspect the speedometer fro allowable indication error and check the operation of the odometer. Reference: Notice: tire wear and tire over or under inflation will increase the indication error. ...

    Blind Spot Monitor operation
    ■ Objects that can be detected while driving The Blind Spot Monitor uses rear side radar sensors to detect the following vehicles traveling in adjacent lanes and advises the driver of the presence of such vehicles via the indicators on the outside rear view mirrors. Vehicles that are traveling ...

    Definition of terms
    Term Definition Monitor description Description of what the ecm monitors and how it detects malfunctions (monitoring purpose and its details). Related dtcs Diagnostic code Typical enabling condition Preconditions that allow the ecm to detect ...