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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    Inspection procedure
    Hint: troubleshoot each trouble symptom in accordance with the chart below. 1 Clear dtc Connect the hand–held tester or the obd ii scan tool to the dlc 3.  turn the ignition switch on and push the hand–held tester or the obd ii scan tool main switch on.  read the dtc . ...

    Removal & installation and disassembly & reassembly
    1. Remove bench type rear seat cushion assy 2. Remove rear floor service hole cover Remove the rear service hole cover. Disconnect the fuel pump and vapor pressure sensor connector. 3. Work for preventing gasoline from spilling out Start the engine.  after the engi ...

    On–vehicle inspection
    1. Connect hand–held tester:  connect the hand–held tester to the dlc3.  start the engine and run it at idle.  select the active test mode on the hand–held tester. Hint: please refer to the hand–held tester operator’s manual for further details. 2. Inspect actua ...