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:

    Electronic control
    Removal and installation of battery terminal  before performing electrical work, disconnect the battery negative (–) terminal cable beforehand so as to prevent burnt–out damage by short.  When disconnecting and installing the terminal cable, turn the ignition switch an ...

    Body panel sealing areas
    Be sure to apply body sealer to the body panel joints and door edges (tip of outer panel folded part), etc., To waterproof and rustproof them. Hint:  apply degreasing agent to a clean cloth and clean the sealer application areas. After removing the applied spot sealer from the se ...

    Replacement
    Hint: components: 1. Precaution 2. Disconnect battery negative terminal 3. Remove front door scuff plate rh 4. Remove rear door scuff plate rh 5. Remove front door opening trim rh 6. Remove rear door opening trim rh 7. Remove lap belt outer anchor cover 8. Remove center pillar garnis ...