Toyota Corolla (E120): Circuit description

In the diagram below, when the engine is cranked, current flows from terminal st2 of the ignition switch to the starter relay coil and also current flows to terminal sta of the ecm (sta signal).

When the sta signal and ne signal are input to the ecm, tr is turned on, current flows to the coil of the circuit opening relay, the relay switches on, power is supplied to the fuel pump and the fuel pump operates.

While the ne signal is generated (engine running), the ecm keeps tr on (circuit opening relay on) and the fuel pump also keeps operating.

Wiring diagram

Wiring diagram

Inspection procedure

    Share this page:

    Other materials:

    On–vehicle inspection
    1. Check cooling fan operation with low temperature (below 83 c (181 f)) Turn the ignition switch on.  check that the cooling fan stops. Hint: if not, check the cooling fan relay and water temperature sensor, and check for separated connector or severed wire between the cooling fan ...

    Inspection procedure
    1 Check side squib(lh) circuit(airbag sensor assy center – front seat airbag assy lh) Disconnect the negative (–) terminal cable from the battery, and wait at least for 90 seconds.  disconnect the connectors between the airbag sensor assy center and the front seat airbag assy ...

    If a warning message or indicator is displayed (vehicles with a multi-information display)
    If a warning is shown on the multi-information display, stay calm and perform the following actions: 1 Master warning light The master warning light also comes on or flashes in order to indicate that a message is currently being displayed on the multiinformation display. 2 Multi-information d ...