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

Inspection procedure

    Share this page:

    Other materials:

    Child restraint systems with a top tether strap
    1 Adjust the head restraint to the downmost position. 2 Secure the child restraint system using the seat belt or LATCH anchors. 3 Open the anchor bracket cover, latch the hook onto the anchor bracket and tighten the top tether strap. Make sure the top tether strap is securely latched. ` ...

    Inspection procedure
    1 Check ignition or starter switch assy Check the ignition switch, as shown in the illustration and table. Standard: 2 Check fuse (ecu–b) Remove the fuse from the instrument panel j/b.  check the continuity of the fuse. Standard: continuity 3 Check relay (m ...

    Diagnostic trouble code chart
    Notice: when removing the part, turn the ignition switch to off. Hint: using sst 09843–18040, it connect the terminal tc and cg of dlc3. If any abnormality is not found when inspecting parts, inspect the ecu and ground points for poor contact. If a malfunction code is displayed during ...