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:
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
1 Turn the engine switch off.
2 Open the fuse box cover.
► Engine compartment
Push the tab in and lift the lid off.
► Under the driver’s side i ...
Riding with children
Observe the following precautions
when children are
in the vehicle.
Use a child restraint system
appropriate for the child,
until the child becomes
large enough to properly
wear the vehicle's seat belt.
It is recommended that children
sit in the rear seats to
avoid accidental contact
with the ...
If your vehicle overheats
The following may indicate that your vehicle is overheating.
● Vehicles without a multi-information display: The high engine coolant temperature
warning light comes on or a loss of power is experienced.
Vehicles with a multi-information display: The engine coolant temperature gauge&n ...


