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:
License plate lamp assy
Replacement
1. Remove luggage compartment lock cylinder & key set
2. Remove luggage compartment door garnish outside
3. Remove license plate lamp assy
Pull the license plate light assy to the side of vehicle as
shown in the illustration and release the claw.
disconnect the c ...
Inspection procedure
1 Inspect terminal voltage(idl)
Remove the cruise control ecu assy with connector still
connected.
disconnect the ecm connector.
turn the ignition switch to on.
measure voltage between terminal 13 (idl) of cruise control
ecu assy connector and body ground when 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 ...


