Toyota Corolla (E120): Circuit description

If the ignition switch is turned to the on position, battery positive voltage is applied to the switches, such as terminal ig of the ecu.

Wiring diagram

Inspection procedure

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    System description
    The ecm uses signals from the vehicle speed sensor and crankshaft position sensor to detect the actual gear position (1st, 2nd, 3rd or o/d gear). Then the ecm compares the actual gear with the shift schedule in the ecm memory to detect the mechanical trouble of the shift solenoid valves, th ...

    Circuit description
    The rotary solenoid type idle air control (iac) valve is located under the throttle body and intake air bypassing the throttle valve flows into the iac valve through the passage. In this way the intake air volume bypassing the throttle valve is regulated, controls the engine speed. The ...

    Inspection procedure
    1 Inspect terminal voltage(idl) Remove the cruise control ecu assy with connector still connected.  disconnect the ecm connector.  turn the ignition switch to on.  measure voltage between terminal 13 (idl) of cruise control ecu assy connector and body ground when the ...