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:

    Inspection procedure
    1 Check p/t squib(lh) circuit(airbag sensor assy center – front seat outer belt 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 seat belt pretensio ...

    Road test
    1. Problem symptom confirmation Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of the trouble. If the problem is that the transaxle does not shift up, shift down, or the shift point is too high or too low conduct the following road ...

    Windshield wiper switch assy
    Replacement 1. Remove steering column cover lwr Remove 3 screws and steering column cover lwr. 2. Remove windshield wiper switch assy Disconnect the connecter of the windshield wiper switch.  release the claw and pull out the windshield wiper switch assy as shown in the ...