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:
Heater & air conditioner
Service data
Torque specification
Supplemental restraint system
Torque specification
Seat belt
Torque specification
Wiper & washer
Torque specification
Audio & visual system
Torque specification
Instrument panel/meter
Torque specification
Seat
Torque sp ...
Inspection procedure
Hint:
if dtc p0441 (purge flow), p0446 (vsv for ccv or vsv for pressure
switching valve), p0451, p0452
or p0453 is output with dtc p0442 or p0456 , first troubleshoot
dtc p0441, p0446, p0451, p0452 or p0453. If no malfunction is detected,
troubleshoot dtc
p0442 or p0456 next.
...
Turning on light switch does not light up night time
illumination of radio receiver
Wiring diagram
Inspection procedure
1 Inspect radio receiver assy(ill+, ill–)
Check that the voltage between terminals at each condition,
as shown in the chart.
Standard:
Repair or replace harness or connector ...


