Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Mil circuit / Circuit description
Toyota Corolla (E120): Circuit description
The ignition switch provides circuit power and the ecm provides the circuit ground that illuminates the mil.
Mil operation is checked visually: it should be illuminated when the ignition is first turned on. If the mil is off all of the time or on all of the time, use the procedure below to troubleshoot it. The mil is used to indicate the ecm’s detection of a vehicle malfunction.
Follow this procedure using the hand–held tester or an obd ii scan tool to determine the cause of the problem and to check the mil.
Wiring diagram

Other materials:
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 ...
Terminals of ecu
1. Inspect integration relay
Disconnect the connector and check the continuity of each terminal of
the disconnected connector.
Standard :
If the result is not as specified, the vehicle’s side may malfunction.
Reconnect the connector and check each terminal.
Standard:
If ...
Overhaul
Caution:
wear the gloves, because the cutting surface of the seat back frame and seat
adjuster may injure
your hand.
Hint:
tape the screwdriver tip before use when prying parts.
1. Disconnect battery negative terminal
Caution:
wait for 90 seconds after disconnecting the battery terminal a ...


