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:
Indicators
The indicators inform the driver of the operating state of the vehicle’s various
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 ...
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs adjustment
or repair. Contact your Toyota dealer as soon as possible.
Visible symptoms
● Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or u ...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove horn button assy
Place the front wheels facing straight ahead.
using a torx socket wrench (t30), loosen the 2 torx
screws until the groove along the screw circumference
catches on the screw ca ...


