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:
Winter driving tips
Carry out the necessary
preparations and inspections
before driving the
vehicle in winter. Always
drive the vehicle in a manner
appropriate to the prevailing
weather conditions.
Pre-winter preparations
Use fluids that are appropriate
to the prevailing outside temperatures.
Engine oil
Engine c ...
Seat belt warning lamp for driver’s seat does not
operate
Wiring diagram
Inspection procedure
1 Check combination meter assy
Ground terminal c9–12 on the combination meter side.
check that the warning lightlights up.
Ok: warning light lights up.
2 Inspect front seat inner belt assy lh
Disconnect the front seat inner belt ...
Oxygen / af sensor heater monitor
Preconditions
The monitor will not run unless:
mil is off
drive pattern
connect the obd ii scan tool to the dlc3 to check monitor status
and preconditions.
Start the engine and allow it to idle for 9 minutes.
Drive the vehicle at 25 mph (40 km ...


