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:
Monitor description
While the engine is being cranked, the battery positive voltage is applied to
terminal sta of the ecm.
If the ecm detects the starter control signal (sta) while the vehicle is
driving, it will conclude that there is
a fault in the starter control circuit. The ecm will turn on the mil and a d ...
Inspection procedure
1 Check door lock
When the door does not operate manually, proceed to ”a”.
when the door does not operate via the key, proceed to ”b”.
2 Inspect door lock control switch
W/ power window:
remove the power window regulator master switch assy.
Inspect th ...
Problem symptoms table
Hint:
if a normal code is displayed during the dtc check but the trouble still occurs,
check the circuits for each
symptom in the order given in the charts on the following pages and proceed to
the page given for troubleshooting.
The matrix chart is divided into 3 chapters.
If the instruc ...


