Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Ecm power source circuit / Circuit description
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
Other materials:
Components
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Problem symptoms table
If a normal code is displayed during the dtc check but the problem still
occurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the
relevant troubleshooting page.
Notice:
when replacing skid control ecu, sensor or etc., Turn the ignition swi ...
Inspection procedure
1 Check tvip ecu
Check that the operation of the tvip function is normal.
Hint:
with this inspection, the tvip ecu cpu can be diagnosed if it works normally or
not.
2 Check wire harness (tvip ecu integration relay)
Disconnect the tvip ecu and integration relay connectors.
ch ...