Toyota Corolla (E120): Diagnosis circuit

Wiring diagram

Circuit description

Other materials:

Location
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Inspection
1. Thermostat Hint: the thermostat is numbered with the valve opening temperature. Immerse the thermostat in water and gradually heat the water.  check the valve opening temperature. Valve opening temperature: 80 to 84 c (176 to 183 f) Hint: if the valve opening temperatur ...

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 supplyin ...