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:
Driving tips
Winter driving tips
Carry out the necessary preparations and inspections before driving the vehicle
in winter. Always drive the vehicle in a manner appropriate to the prevailing weather
conditions.
Preparation for winter
● Use fluids that are appropriate to the prevailing outside temper ...
Inspection procedure
Hint:
start the inspection from step 1 in case of using the hand–held tester and start
from step 2 in case of not
using the hand–held tester.
1 Read value of hand–held tester(front speed sensor)
Select the datalist mode on the hand–held tester.
check that there is no differe ...
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 ...


