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
    1 Inspect dlc3 terminal voltage(ts terminal) Turn the ignition switch to on. measure voltage between terminals ts and cg of dlc3. Ok: voltage: 10 – 14 v 2 Check harness and connector(dlc3 – body ground) Check for open and short circuit in harness and connector between ...

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    Opening the trunk
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