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:
Inspection
1. Thermostat
Hint:
the thermostat is numbered with the valve opening temperature.
Immerse the thermostat in water and gradually heat the
water.
check the valve opening temperature.
Valve opening temperature:
80 to 84 c (176 to 183 f)
Hint:
if the valve opening temperatur ...
Warning lights
Warning lights inform the driver of malfunctions in the indicated vehicle’s systems.
*1: Vehicles without a smart key system:
These lights turn on when the engine switch is turned to the “ON” position to indicate
that a system check is being performed. They will turn off after the engi ...
Using a flat bed truck
If you use chains or cables to tie down your vehicle, the angles shaded in black
must be 45°.
Do not overly tighten the tie downs or the vehicle may be damaged.
■Before emergency towing
1 Vehicles without a smart key system: Put the engine switch in the “ACC” (engine
off) or “O ...


